Posts on this page:

Lost in Translation:
An NEC PC-98 English Documentation Project

The Hidden World of Old Japanese Domestic Computers

This page is under construction!

Please note that the writing of this blog post is currently underway, limited by my available time to work on it between work, my job search, and schooling. It may have omissions, have broken links, drop off mid-sentence, or have any number of other issues until it is completed. But I WILL finish it.

Additionally, I have a friend who is writing about her NEC PC-9821's, which she got at around the same time I got my PC. Her work will likely appear here, too!

1 Nov 2023 []
A good friend of mine recenty convinced me to dive headfirst down the rabbit hole of things I didn't really understand: old Japanese domestic computers, and particularly the NEC PC-9801 series. After seeing the relatively lacking English language documentation available for these systems, I now want to document and help others on their own journeys to discover more about these computers themselves. Perhaps it will even be an interesting read for someone who doesn't intend to get one!

So far, this article is on track to be longer than even the Bubblegum Crisis posts that I wrote before. So again, be warned.

I anticipate that this page is going to get rather long, so I'm providing a Table of Contents for the core of this post (everything after the introduction).

Table of Contents

Firstly, the Backstory


This is mostly a personal section, detailling my philosophy behind why I'm doing this and how it came about. If you just want to know about the computers and get into the meat of this post, you can skip this part and go further down to the introduction, or find the point you want to jump in at back in the table of contents.

I recently ended up with a Japanese PC of my own. I got it in part so I could help a good friend of mine with a passion for pixel art and a fascination with old Japanese computers to dive into and embrace that passion for old electronics. I have been swimming in this passion for a long time now, but she had felt that it was out of her reach before she met me. So my main reasons for getting it were that:

  1. I would enjoy learning more about it, too,
  2. My friend was already determined to get one,
  3. I had considerably more pre-existing knowledge about DOS and SCSI and other "old computer things" than she did, and
  4. I could maybe grease the wheels of learning for her, and help both of us to get off the ground faster.

I think that ended up being a good decision. Old computers aren't like most old game consoles; there's a lot more stuff to go wrong with them, and parts are more varied and harder to come by. Documentation is much more important, and not everything is going to "just work" if plugged in.


Everything's Better with a Friend!

So in short, I wanted to accelerate my friend's rate of learning by being able to answer her questions as they arose. When I was learning, I didn't really have anyone I could ask these kinds of questions a lot of the time. Even when I was able to eke an answer out of someone (on IRC or wherever), it was often still a little confusing to me, and I didn't want to encroach further on peoples' time by asking too many follow-up questions and end up annoying them. In these kinds of conditions, just learning about the basics of things can take a pretty long time. Plus (just between you and me), I'm not naturally inclined to thinking in programming terms, I think. I know people who were wizards making NES games at age 18, but that was never me. I think I was still basically in the "learning C" stage at that point in time.

Pretty much nothing has come easily for me, and I didn't have many to guide me, since for the most part the stuff that I'm talking about right here and now is not commercially viable (thus, courses are not offered on most of it besides C and Unix). So I think you basically have to either know somebody or else do it the hard way like I've been doing it and scrounging around for all the little pieces and trying to make sense of them.

Learning language is much the same way, I think; if you know someone and are regularly in contact and interaction with people who speak the language, it's much easier than if you are trying to learn just from reading the language without that interactive element. But I want to have fun in my spare time. So learning a language by going to classes and stressing out about my GPA– learning on a crunch not because I want to, but because I have to or else my future is ruined, is not ideal for me.

That's how learning Japanese has been for me, too. Mostly through reading and listening. Ideally, I'd have other people who were better than me at the language to try to converse with in it who could help me along, but that's just a little tricky to come by in Indiana.

My point with these examples is that I think I didn't get much handholding early on, and that I think I may have gotten to where I am more quickly had I had access to more people whom I could ask my questions of (and who were freely sharing knowledge with me). I'd like to be that person for my friend– and maybe also for others who read my post, so that's how this all started.

The Tower of Babel is Populated Solely by Engineers

I also think a lot of engineering types, even brilliant ones, are kind of bad at communicating the things they know in ways that we mere mortals may endeavour to understand them. One only has to look at wikipedia articles on mathematics– or maybe on something in physics, like color temperature, to realize the breadth and severity of this problem.

That article is perfectly accurate in what it describes, but it is nearly useless for someone like me who was only trying to look up why color temperature exists and how it's actually measured or quantified.

In that example, the crucial thing I was missing was what "black-body radiation" is, but the article on it lacks good practical examples in plain view, so all it does is overwhelm me. It is actually something that many people have seen before, without even realizing it. It's the reason that heated iron (from, say, a blast furnace) glows red when hot– and white when even hotter.

The key point that is missing (or presumed to be already known) is that everything can glow like that if it is heated enough compared to its surroundings. Color temperature is measured in kelvin because it can be most easily quantified by describing how much warmer than absolute zero a perfectly black object (one that does not reflect any light that strikes it) would need to be to glow with that frequency (and therefore color) of light.

Anyway– because I didn't have someone to explain things like that to me in one place, particularly the iron glowing example, it took me years to figure out what color temperature actually meant. In this case, with this old technology, I also can have trouble finding clear explanations of how things work.

Try looking up information on how to write a DOS CONFIG.SYS file, for instance, or maybe try to find a number in a little-endian hexadecimal dump without realizing that all the numbers are going to be in reverse byte order from what is most intuitive. So, if looking for hexadecimal 0xDEADBEEF, you'd need to search for the byte sequence 0xEFBEADDE on things like Intel computers). Good luck figuring that one out on your own if no one's explained endian-ness to you yet!

I know there's a lot of information on this page, but maybe by trying to describe everything in a somewhat reasonable order and by describing terms as they come up, I can avoid some of the failings of Wikipedia at being approachable. To this end, I also have a table of contents, so that one may jump straight to the thing that interests them, and jump back for a definition or prerequisite knowledge as needed.

My hope, then, is to at least help people to at least know what questions to ask, and perhaps some terms they need to search for. Ideally, I'll also be able to answer most of those questions on this page clearly enough that the searches are all but unnecessary. I want this article to somehow manage to be understandable without talking down to anyone. I hope to be able to strike such a balance, and to learn what does and doesn't work when teaching others.


Co-Op Mode

To that end, I think that my friend will probably end up collaborating with me on this. I think that her insights and sharing what stuck out to her can help me to avoid falling into the engineer's trap of assuming that others understand the underlying concepts of their ramblings without them having to fully explain it in a way they can grasp. And I also am interested to see how much she's learned! We've known each other for just over a year, and she's made leaps and bounds.

Anyway, if that's the case, and she does contribute, then this may be a joint post! I'll let her decide how much she feels like sharing, though. I think we will be trying to compartmentalize into sections, so it's somewhat clear who's who. But this article is still under construction, so be warned!

Alright, you ate your vegetables. And now, here's the meat of the post.


Introduction to Japanese Computers

To be honest, I've always been more of a Sharp X68000 person than a PC-98 person, myself. Not because there's anything wrong with the 98, though!– the X68000 is just a much more powerful computer if you are interested in playing games, with much stronger graphical capabilities in most respects than its competition. It also helps that the source code for Human68K (the OS) is available freely.

Unfortunately, the X68000 has a few problems if you're looking to obtain one in 2023:

…Hey, wait a moment. Haven't I seen this somewhere before?

Amiga 4000 prices on ebay, $3000 plus.
The X68000 seems to be pretty much analogous to what the Amiga became here.
I'd rather buy a decent used car, personally.

So basically, much like with Amigas, the continual interest in the platform from people with more money than I have has ensured that I've written off being able to afford and justify getting an X68000 in the near future, barring incredible luck. But I'm still interested in Japanese computers; there are a lot of weird designs out there that are intriguing to me, and some of them look absolutely gorgeous.

The Sharp X1 computer looks beautiful in red and black.
The Sharp X1. I wish any of my computers looked this good!

I briefly had considered an X1, which looks stunning, and would also be able to run CP/M. But unfortunately (again), there's not much I think I would actually do on one, no matter how beautiful it would look on my desk. Maybe if I can find a good thing to do on it some day, I'll return to thinking about it. The monitor would be pricey, I bet, but the X1 computer itself regularly shows up for pretty fair prices online, even in red (the objective best color for it).


Some Reasons NOT to Buy a Japanese Computer

So, basically, I'd been considering getting into Japanese computers for some time, but never following through. Even ignoring the initial cost at auction, the shipping fees would be murder on top of that… and there are all sorts of other considerations that I'd have to make when buying one, as well, to actually be able to use it here. For instance, what kinds of floppies will they use? Do I want to use real floppies, or Gotek-style floppy drive hardware emulators and disk images? How will i connect a hard drive? How do I actually power the thing? What kind of software can I practically use on it? What kind of screen do I need?

As you might be able to see, it quickly becomes a logistical nightmare and a money pit. I'd experienced some of this with my Amiga 500, but was lucky enough to get mine with a correct monitor and hard drive and power supplies included in the sale at a really nice price, locally, with no shipping fees. But I'd still felt the need to upgrade to a newer hard drive and caused endless SCSI headaches in the process. I'd upgraded the RAM, added a Genlock to subtitle laserdiscs, put in an ECS (enhanced) version of its "Denise" chip to enable higher resolutions, added a Kickstart (bootloader ROM) switcher to let me boot newer versions of Amiga Workbench (the OS), and all sorts of other things to better use it. All of that stuff adds up fast! And to do the same on a Japanese computer, many of those purchases would include paying shipping fees from about halfway across the planet whenever I ran into a new problem that needed a hardware solution.


Why I Still Ended Up Getting a Japanese Computer Anyway

So, knowing all of this would happen, and that it'd be a massive money pit, why did I decide to follow through, eventually?

Well, basically, it was because of my aforementioned good friend with the pixel art passion. I have been helping her on her journey into older computers, which were already an interest of mine. That, combined with my own predisposition towards interest in old computers, was enough to motivate me to bite the bullet. I knew that she'd have an uphill battle learning to use one on her own, and that it'd be more fun (and simple) for me to help if I had a physical computer of my own, too.

By the way, the main reason it would be an uphill battle is that she had no prior DOS experience in any language, and no exposure to things like drive selection jumpers/switches (for IDE hard drives and Shugart interface floppy drives), maintaining and cleaning floppy drives, formatting floppies for a system that expects 1232KiB disks, or transferring information to a PC98 from a modern PC in general. Things can break in so many subtle ways with old tech like this, and if you don't know what to look for it can be incredibly frustrating. Also, if you want to be able to afford it, you often have to look at listings for stuff in untested or "junk" condition. Knowing what the signs are that something will likely work or be fixable is an art in and of itself.

This lack of experience can of course all be overcome, but it's a lot of learning to do. I figured I could help speed up the process if I helped a bit. There'd still be stuff I didn't know about, but at least some of my knowledge from other old computers does transfer over. I'm happy to say she took to it with gusto, and has learned a ton over a very short span of time! And it feels great to have an eager and enthusiastic learner who asks all the right questions like she does. It's hard for me to believe that about a year ago she was hesitant to take apart an old laptop to swap the lid, and now she takes everything apart the moment she gets it, just like I do. :)


The NEC PC-9801

Why Do People Get a PC-9801?

My aforementioned good friend had long been enamored specifically with the NEC PC-9801 and its descendants. To be completely honest, the PC-98 has some games with good artwork and stuff, but it was the least interesting of the major Japanese platforms to me. It was the one that sold the best, and it wasn't particularly speedy or performant. It also used x86 CPU's, which means it was the most "IBM-Like" of the big platforms, alongside Fujitsu's "FM Towns" line. But the FM Towns had more interesting graphical capabilities for playing games and multimedia. The draw for the PC-98, for people interested in games, seems to be one of three things these days.

Battle screen from a game, Emerald Dragon.
Emerald Dragon (1989), an RPG that I like by Glodia for the NEC PC-9801.
  1. Touhou, a "bullet hell" type shooter game series featuring cutesy manga/anime style girl characters which started on the PC-98 platform. I'd say that (at least from what people say online and the frequency with which they say it) this one franchise accounts for maybe 40% of the gaming interest in the platform, both inside and outside of Japan. The Touhou franchise is still ongoing, so that's probably a large part of why it has stayed popular while everything else is forgotten.
  2. Early PC-98 era computer games, aimed at a general audience. Later in the system's lifetime, most people interested in computer games moved to other platforms. This means either to game consoles like the Famicom, Super Famicom, Mega Drive, and so on, or to other computer platforms like the aforementioned X68000 (which had some excellent arcade ports) or the FM Towns. Some games in this category of early general audience games for PC-98 include some great RPG's you may or may not have heard of, such as:
    • Falcom's Ys franchise, which survives to this day.
    • Glodia's Emerald Dragon, which has a translation on the SNES version… but I like the art on the PC-98 version the most.
    I'd say that this interest accounts for maybe 5% of the outside-of-Japan interest in the system, and I'd guess maybe 15-25% of the interest within Japan.
  3. Finally, I can't just dance around it forever, so it's best to just address it here. Later in the system's lifetime it became a staple for visual novels and erotic games (abbreviated as eroge). It was very well suited to this, since even though its actual performance at animating things on the screen was rather poor, it could display somewhat high resolution static graphics in a fair number of colors. So it was ideal for visual novels. I'd guess that internationally this is a large amount of the interest and in Japan it's about 35% of the interest. I am not personally very interested in that (I am basically asexual); the hardware itself is much more interesting to me.

Additionally, there may be some more interest if someone wants to run Linux or similar on it, since buying a domestic 486 PC is not significantly less expensive anymore.

To be honest, the visual novel and eroge element probably is what interests me the least of the above about the 98; I am interested most in the computer RPG's that we never got here, both as a way to learn some Japanese and because I enjoy the art styles, music, and stories. I played a small portion of the English translation of the SNES version of 'Emerald Dragon,' and it looks like it might be really, really good storywise. I also have played an emulated version of 'Ys' and I loved the soundtrack (which was composed by Yuzo Koshiro, who later did the music for Streets of Rage and is often considered a master of frequency modulation synthesis music).

It also can have a Yamaha OPN series frequency modulation (FM) sound chip - I'm not aware of any cards featuring this chip on IBM compatibles (that is to say, ISA cards). The only things in the west that I can think of that have similar sound chips are the Sega Genesis (YM2612) and Neo Geo (YM2610)... but the YM2608 is more advanced than either of those in most ways.

Sure, there are a handful of visual novel-esque games that I would really like to play, though. Hideo Kojima's acclaimed Snatcher comes to mind, for instance. But that had a Sega CD port (in English, I might add), so why not just play that?!


Why Did I Get the PC-9801?

(The Influence of Friendship On Financial Decisions)

In the end, the primary reason i was interested now was because of my friend, who has less technical background than I do but who has strong interest in learning - not just about the PC-98, but about computing and old electronics in general. She has wanted a PC-98 for a long time, and asked for my help in figuring out what to get and how to set it up.

I decided that it might be fun for me to get one, too, so we could figure stuff out together. And such were the mental gymnastics I did to get into a buying mood. It also is a somewhat smaller investment than an X68000, and with a LOT more supply available for sale in both computers and the parts for them, with less intense demand.

I have already had a lot of fun teaching my friend and watching her gain more confidence with electronics. It seems to have been something she had wanted to get into for some time, but didn't know where to begin. Having been there myself, I suppose I took some sympathy. My desire to share what I've learned with others also kicked in, since sharing what I've learned is what I live for. Coupled with my own shelved (out of practicality) curiosity about these platforms. It simply felt like it might finally be the right time.

We had talked a lot about older computers in the past, and I expressed that I was somewhat familiar with the Japanese computer platforms, at least in theory. And it seemed like a fun thing that we could do together. So far, it actually has been, although there have been a few bumps in the road. I'll hopefully get around to explaining what exactly those bumps are soon. At any rate, I had to start researching the PC-9801 series in earnest to prepare us for our respective purchases.

And so, without further ado, I bring you…


Wyatt's PC-9801 Buyer and User Guide

Companion Videos

Before we begin, I should note that I have made a few videos about various bits of stuff that I try to cover in more depth here. I linked to the video and this blog post on Reddit a week or three ago, and someone said they'd already stumbled across my blog but didn't know I made videos. So I realized I should probably let you know that I do in fact have a Youtube account.

If you would like to see a video, You can watch the most useful/in-depth one I've made thus far here to accompany this text. But if I say something in the video that appears to be contradicted by this post, trust this text as the more authoritative source!– Hey, I definitely make mistakes sometimes. Especially since I'm not using a script.

(Screenshot of my 'youtube channel' as it existed on 10
               January 2024.)
I'd love to hear what you think if you watch any of the the PC-98 videos. I'm pretty new to this.
I will try to reply if you leave questions or meaningful comments, since I don't currently have a way to let you ask your questions on my blog.

Note, by the way, that my channel is not currently monetised; I hate ads. if anyone really wants to throw money at me, I wouldn't say no. But I don't really do this expecting anything except for hopefully some appreciation and/or general interest, as much as money would be appreciated and useful. :)

Alright. Now that we have that 'plug' out of the way, let's get started!

Getting Started

First off, let's address something very basic but of absolutely critical importance for understanding fully what you are about to get yourself into, and how deep you can expect to get into it.

The PC-9801 is NOT an IBM Clone!

If you came here looking for info on the PC-98 series, and aren't just casually reading my blog, then you should already know this– but the NEC PC-9801 and its descendants are not just fancier IBM PC's. They do have some similarities, on account of their chipsets, but if you want to run programs written for an IBM that do ANY BIOS calls or direct hardware access, you can expect that it will likely not run on a PC-98. If it only uses MS-DOS/PC-DOS API's, though, then you might be fine.

For starters, don't just expect that you can install your American copy of MS-DOS on a PC-98 and have it work. It will not work. You will also have to be able to figure out how to use DOS in Japanese; this is most probably totally unavoidable. Things that have been unofficially translated for the PC-98 are quite scarce compared to all of the impressive accomplishments that have been made by ROM hackers and fan translators for game consoles and newer Windows games.

Here are some of the hardware and software architectural differences between the PC-9801 and IBM-compatibles (known as DOS/V systems in Japan) that I have encountered so far, in list form.


Choose Your Kart (Computer)!

So, ya really want to learn about the PC-9801, do ya? Well, first, what do you want to do with yours? - depending on your answers to the below questions, some models may be preferable over others.

Since there was never a "PC-98 building industry" to my knowledge, given the proprietary nature of the platform, you will have to settle for an OEM-made machine. This makes choosing the correct one for your needs even more important, since it's much less likely you can just pop something out of a socket and upgrade it later (on many models). Many have soldered-down CPU's, for instance, which obviously precludes most people from being able to upgrade them.

The PSU's are similarly designed for the power budget of the machine as it came configured, with some overhead for cards. The connectors are not necessarily going to be standardized, and I doubt that most will accept an AT or ATX PSU. So if you want to upgrade your PSU, you may end up having to hunt for a related model that came from the factory with a beefier PSU to steal parts from - or perhaps you will be able to do a custom wiring job, if you're confident with that, and make some other PSU work.

Finally, even if something looks like a standard connector, don't take that for granted. Do your research first! Don't just assume the best of all possible worlds, where everything works with everything, because I think it's safe to say we aren't in Kansas anymore.

(Bubblegum Crisis PC-98 game screenshot, looking up at
                    Genom tower, with logo to the right of the image)
…And we're not in Kansas anymore because we're actually in Megatokyo now.
(Yes! - There's a Bubblegum Crisis game on the PC-9801!)

Regarding the above picture, Bubblegum Crisis is actually an example of a game where the system you choose matters. The game uses FM sound, so it needs to be new enough for that, and it also makes no attempt to throttle itself to match the framerate of the screen - it just runs at full-tilt all the time, so you have to be able to make the computer run slow enough for it to be playable. It's comically fast at 75 MHz.


DOS, Windows, or Other?

If you intend to get a PC-98 and run Windows programs on it, you can basically treat it as an IBM-compatible PC running that version of Windows, except with a Japanese locale. I see little reason to do this, unless you really want a 486 running Windows but don't like the prices on IBM-compatible 486'es.

It has also been said by many that the 98 series lost its "98-ness" in the mid 90's with the rise of Windows, as the computers moved away from the old µPD7220-derived design to using third-party GPU's that were more adept at accelerating 2D window management operations. These graphics chips were things made by companies like S3, and stripped away another bit of uniqueness from the series. Later models also introduced features like PCI card slots. The PC-98 series rapidly moved towards being just a "Windows PC," compatible with win16/win32 programs made for IBM-compatible Wintel machines. DOS compatibility still existed to an extent, but the further away NEC moved, the more stuff began to break in DOS-land, where direct hardware access was still king.

Thus, it seems that the PC-98 might have been one of the last non-IBM-compatible, non-Apple consumer personal computer series to survive in any form. But if you want to run Windows, why not just run Windows on an IBM-compatible...?

In my personal opinion, the real reasons one should want a PC-9801 are some combination of game software, potentially learning Japanese, and maybe running free operating systems like the BSD's or Linux distros. There is very little attractive about the machines for plain old Windows use. In my case I keep a Gateway E-3200 (Pentium 3) around for my old Windows software use. It runs US English Windows 98 and Japanese Windows 2000, and packs a Voodoo3 GPU; this puts me in a good spot for anything I might really want to play in the Windows world, since I'm not really too interested in modern Windows games.

You Have Selected: DOS

I will just assume you can take a hint and realized that above I was essentially saying that DOS is the only real choice here for games, if you don't want your computer to be "just another old Windows PC."

The rest of this article will probably not focus on Windows much, if at all. Maybe I'll cover N88-BASIC and/or other OS'es, some day, though.


What are My Options for Hardware, then?

I stumbled my way into my choice based on a combination of factors. First of all, as mentioned above, I wanted it to be viable for DOS games. I also wanted it to be new enough to be able to run the same things my friend was running, which are largely from the era where the games don't look quite "8-bit" anymore and the pixel art can be more intricate. I also wanted it to be capable of FM sound (Yamaha YM2203 or YM2608). These chips have a lot in common with the YM2612 chip used in the Sega Mega Drive/Genesis consoles. I also desired expandability, the ability to use a hard drive, and to be honest I sort of wanted to do something no one else was doing.

So, if you want a PC-98 for DOS, and you don't want to buy one for early games and another for late games, I'd say a 486 or 386 is the ideal range to choose from. Circa perhaps 1990 to 1994. You can find a list of a whole bunch of machines on this site.

First, I helped my friend to choose something. She already kind of knew what she wanted, so all I really had to do was cross reference the models she talked about with the ones on that site to check for red flags.

PC-9801 or PC-9821?

The PC-9801 was the original series of computers. The best way to describe the differences might just be to show how the PC-9801 and PC-9821 lines tended to differ.

This distinction is for the most part illusory. There are certain things correlated with one series or the other, and the original target markets for the two lines were different, but being badged a "PC-9821" originally was supposed to signify that it was "Windows-ready" and better for multimedia, as far as I can tell. Some PC-9821's were still sold with just MS-DOS installed and without hard drives, so 9821 does not necessarily mean "Windows" in all cases.


The PC-9821 models came out targetted at use by Windows users, and have some quality of life improvements. For instance, to change settings on a PC-9801, you flip a bunch of DIP switches and need to have documentation to discover what they do (they are not necessarily marked on the board). But with the 9821, by holding the 'HELP' key while booting, you can enter a software configurator which shows you virtual dip switches that you can flip, with inline help text describing what each switch is doing. It can be a real time saver.

The 9821 line also usually has different floppy disk drives - from what I can gather, the 9801 series usually had 5.25" and the 9821 usually had 3.5". Since 3.5" floppies are a LOT easier to come by in good shape, and just generally age a little better, that may be one reason to consider using a PC-9821 if you intend to keep the original floppy drives.

It should be noted that on the PC-98, it is possible to write any PC-98 5.25" floppy disk image to a 3.5" floppy disk and it will work (if the computer and drive both can handle the density/coercivity of the media). You may have to reformat the disk first if using a western market disk, but 'ufiformat' on Linux can do it. This is to say, the PC-98 treats 3.5" floppy drives as just miniaturized 5.25" drives, with the same numbers of tracks and sectors as a 5.25" disk. Later ones (mostly 9821's) can also support 1.44MB formatted high density disks, but most software was distributed on 1.2MB disks.

A 9821 is also much more likely to come with an IDE hard disk drive, or at least with a controller and connector for one. Typically, with a 9801, you need to use a SCSI controller and SCSI drives to get large storage capabilities. I personally struggle to make SCSI do what I want sometimes, and documentation on many PC-98 SCSI controllers seems relatively poor, so that might be another argument for using a 9821.

As will be seen below, there is one major reason apart from CPU speed (and even more important than CPU speed, arguably) not to get most 9821 models: western graphics accelerator chipsets for Windows which are not entirely compatible with DOS games written with the uPD7220 and its evolutions in mind. Some may work, some may not. Read on.


The 9801's were intended to be DOS machines; it may be easier to find a low-powered one, and it will definitely be easier to find one without a window accelerator GPU built-in. They seem to be generally less desirable than the early 9821's. Also, this is just something I have heard, but people say it's harder to open up the earlier 9801's (although later ones are probably pretty okay).


Yeah, But What Does All of That Mean?

I threw around a lot of terms describing the differences between the 9801 and 9821. To elaborate a little, here's some more detailed explanations of what you should try to look for or avoid.

Red Flag #1: Leaking Real-Time Clock (RTC) Battery

The one reason I hesitate at all to suggest buying an untested PC-98 is that some of them use Nickel-Cadmium (NiCad) real time clock batteries. Every system with one of those should be treated as a time bomb, if not already dead. Those NiCad battery barrels seem to be more common in older stuff. But they are mounted to the motherboard, so when they leak out, they start corroding the copper traces away. If it's not caught quickly and treated/cleaned, it can and will kill motherboards. If you're not sure which kind of battery a particular model uses, proceed with caution.

(Picture of a corroded Commodore Amiga A501 memory
                    expansion board, destroyed by battery leakage)
My Commodore Amiga A501 memory expansion board - another victim of clock NiCad battery leakage.
Oftentimes with old computers, the battery is on the motherboard itself, and it takes the motherboard with it.

If your system has a barrel battery, I suggest IMMEDIATELY clipping/removing it from the board, buying a new battery cell, and mounting it in a holder attached to the motherboard via a wire. If there was leakage but the board still works, you should polish off the area of leakage (down to good copper), use a little alcohol, and then re-seal it with nail polish or something similar.

It's worth noting that not all RTC batteries are NiCads. I've also seen rechargeable coin cell batteries, which seem to be much more reliable.

The ones that my friend got ended up not having barrel batteries, but I believe the PC-98DO has one and lots of others besides also do.

Red Flag #2: Integrated window accelerator graphics chip

Onboard window accelerator cards are for making Windows run with nice effects, like showing the contents of windows while dragging them around. Unfortunately, these machines force you to use that graphics chipset; there's no way to just "unplug" it and go back to using the old µPD7220 derivatives. So my friend needed to rule out most of the PC-9821 line. But, some of the early ones still had either no GPU card built in, or else simply had an accelerator card pre-installed that could easily be popped out.

Red Flag #3: No FM sound

Some later systems omitted the FM sound, especially laptop PC-98 models. We didn't look at the laptop models in much detail, though, since my friend very clearly expressed that she wanted a desktop model. Early models lacking FM sound are far too old to be able to play any but the oldest PC-98 DOS games at a decent speed.

From what I can tell, NEC never made any laptops with FM sound that did not have a built-in graphics accelerator of some kind. So beware. However, in the section about what I bought below (I did not buy a laptop), I will mention one or two possible workarounds. The first is to look for some Epson computer models; the second is to find a YMF288-based FM PCMCIA card for partial compatibility. One such card is the Panasonic CF-VEW213P; I have also seen talk of QVision Wavemaster cards that accomplish the same thing. Neither will be cheap, but maybe after shipping it's better than importing a desktop?

There are other PCMCIA FM cards for the laptop/note models listed here on this Vogons thread, and maybe even more of them that I haven't heard of. I decided high prices for partial compatibility wasn't something that interested me.

There are two main kinds of FM sound chips to consider; the "26-Sound" and "86-Sound." If your system has 26-sound, it's much better than nothing, but be forewarned that you might still end up springing for a PC-9801-86 sound card board if you want stereo sound, PCM audio playback, or Atari-style joystick compatibility. And that card on its own seems to cost upwards of $100 USD. So factor that in when ordering.

The PC-9801-26K card is a cheaper option, but still over $50 plus shipping. And if your machine isn't new enough to have an integrated 26K, then it may be too weak for most later DOS games graphically and processor-wise.

Some 9821's (early ones) have the "86 Sound" (YM2608) built-in. On these systems, you can connect a joystick to the system via an adapter that plugs into the keyboard port. Basically you need to ground one or two wires and then hook the remaining pins up to the joystick inputs. People on yahoo auctions will sell you pre-made adapter cables, and I didn't have too much trouble finding instructions for making one. Nevertheless, I still made an adapter wiring diagram graphic further down in this article. Given how much devotion I am putting into just writing this article as it is, these diagrams take a long time to make, so I always hesitate to take the time to draw one out – the VGA adapter diagram elsewhere in this post took over an hour to research, draw, and make it look all nice in the page. So did the other mouse adapter one. But the text-based drawing of the adapter didn't look right in anything but specific fonts, so I felt it prudent to make a graphical version instead.

Red Flag #4: No CD Drive

This isn't an instant "NEVER buy this" or anything, but if you don't have a CD drive built in, you may have to add one via a SCSI controller card for some games. So be sure to factor in that additional cost, if having a CD drive actually matters to you.

People have been doing work on adding CD digital audio (CDDA) playback to solutions like SCSI2SD (ZuluSCSI), but as of my writing this it seems most if not all existing ZuluSCSI boards do not have the necessary hardware wired up for audio output, so there is still value in a physical CD drive, even beyond it just "feeling right" - but if you don't need music via CD playback, then ZuluSCSI boards can emulate a data CD drive, which is enough for installing something like Windows 98 or some games.

Also, if you do this, you should probably try to find an NEC branded external drive, since while there is a generic driver, it is buggy with CD audio playback and I've not managed to fix it yet or find anyone else who has already done it for me. NEC's drivers only seem to like NEC's SCSI drives. For data (non-music playback), the third party driver works fine.

Red Flag #5: There is no Red Flag #5

If you avoid a window accelerator built into the motherboard, and your system has FM sound built in (especially a YM2608, for "86-Sound"), you have already ensured that your system will be at least largely compatible with most older DOS things. If you have a CD drive and a non-leaked (or coin cell) clock battery, that's even better.

I guess I could say "dirty computers are less likely to be good than ones that look well cared for," or that "rusty computers are a red flag," but it really depends on where the rust is and the extent of the rust. There are other things I might be able to say, too, but I can't think of them offhandedly and the above are the HUGE ones.

An untested computer is much, much, much more likely to work than one that is listed as being broken. In my experience, with most things that aren't overly mechanical in nature, operation can mostly be taken as a given unless otherwise specified. And you can get much better prices for untested stuff a lot of the time. Plus, if it doesn't work but was untested, sometimes I've been able to fix it up without much effort compared to one that was (for instance) known to be killed by a lightning strike.

I might just add that you shouldn't be dependent on the hard drive (if yours is sent with one) still working. Have contingency plans.


What My Friend Bought (and Her Experiences)

My friend chose to get two systems, a PC-9821 Cs2 and a PC-9821 Ce2. I believe the idea was that if something was broken, she'd be able to swap parts to get at least one system working fully. It ended up being a good thing that she did get two, which I also intend to talk about in detail later, but for now suffice to say one of the floppy drives was unreliable and one of the CD drives didn't work. There was also another little incident after arrival that made it doubly good that she had both systems. More on that later.

(Don't like it? Send me better ones! I've been waiting for them!)
(Also, write your article; you've had about a month so far and I want to hear your thoughts before you start forgetting about things!)

(Image of an NEC PC-9821 Ce2 computer on a desk, along with various peripherals and a little software.)
One of my friend's PC-9821 Ce2's.
The Ce2's original keyboard is on the far right; the 9801V board just feels infinitely better to type on.

Actually, she initially bought two, but ended up with four after a couple of misadventures. She accidentally scratched some traces on the motherboard of her first Ce2 and bought another Ce2 (PC-9821 number 3) to replace it; then, right after she placed an order on that, I found a really, really nice condition Ce2 with absolutely no corrosion that had everything but the monitor. I believe I found that by searching for "PC-9821ce2" (or maybe "pc9821 ce2") with different spacing and punctuation. It was in too good of shape for her to pass up.

I still believe I will likely be able to fix the Ce2 with the cut traces if she ever sends it my way, and also that she might be able to do it herself if she keeps it around for a year or two while practicing soldering on other things in the meantime. But for now, she has three working units and one that will probably work fine once the traces are repaired.

She didn't at first realize why it had failed; it stopped working after she took it all apart and put it back together, and sent me a bunch of photos of the motherboard for me to inspect. She had rested the floppy drive mounting cage on the motherboard and probably run it back and forth along those traces, basically sawing through them.

In my opinion, they look much cuter than the computer I ended up getting, but that's fine. From what I can tell, I like both hers and mine.

(If she sends me some nice pictures, they could appear here soon.)


What I Bought (and My Experiences)

Me? Well, I pretty much just ignored all of the above options. NEC? Pssh. That's so mainstream. I can do better than that.

Sorry for the misdirection! - There was actually a third option (beyond the 9801 and the 9821) which I purposefully neglected to mention. The moral is, don't let people like me make you believe that only what we're presenting are options! Even if I don't mean badly, I could simply be misinformed or underinformed. I highly suggest not leaning just on one or two people's buying guides. There's probably a lot I'm leaving out, just like others have left things out of theirs.

Of course, if you discover errors or oversights, or have more to share, I'd love to hear about your experiences. My contact info is on github and gitlab (username: wyatt8740) in my commit logs for the projects I have hosted there. I'd share my address here, but I'm not too good at munging addresses for avoiding spambots.

So, without further ado, allow me to introduce you to the third option: my Epson PC-486GR (from 1992)!

Epson PC-486GR, set up on my desk with mouse, monitor, flashfloppy drives, and keyboard.
Yup. That's masking tape.

It covers a few of the requirements above, but also lacks a fair number of them. I think it should be expandable enough to accomodate most of it.

Seiko Epson made PC-98 compatible clone computers in the 1980's and 1990's. It seems to be the only company that ever did, strangely enough... apparently, other companies considered it but were worried about the loss of reputation that would be involved. And NEC definitely was hostile to the idea of competition; they locked Epsons out from using its versions of DOS and some of its PC-98 expansion cards in software.


Epson Compatibility

There seems to be a lot of FUD (fear, uncertainty, and doubt) regarding the Epson clones' compatibility on the English-speaking web, so a large part of my reason for choosing this was to call FUDders out on their voodoo brand-name attachment (and just generally prove that they are wrong to worry about it).

"EPSON[...] once made PC-98 compatibles, referred to as "98 Progress". The EPSON PC-486 and EPSON PC-586 are said to be able to run Touhou games, but little is known in general about these computers outside of Japan. What I DO know is that they run MS-DOS for PC-98, so they are software-wise compatible[...] If you plan on buying one of these, please be very cautious, because the full extent of the EPSON PC's compatibility with the NEC98 standard is currently uncertain."

(Emphasis mine.)

I think that person is trying to be helpful, but to me it reads as someone who is (intentionally or not) promoting FUD and potentially scaring people away from something that should not be so mystical.

I was able to do a little research before buying mine, and there was plenty of talk about the Epsons on the web (in Japanese) and I did not find a single mention of incompatibility other than in that NEC itself added "Epson checks" to some of its cards' boot ROM's and to some versions of NEC's MS-DOS variant for the 98 series that would make the computers fail to boot (an act of blatant anticompetitive sabotage, if you ask me). See also Microsoft's attempt to sabotage Digital Research's DR-DOS by scaring customers into thinking it was incompatible with Windows 3.1 beta, when it actually worked fine if not for code in Windows 3.1 explicitly designed to generate fake error messages.

"What the [user] is supposed to do is feel uncomfortable, and when he has bugs, suspect that the problem is DR-DOS and then go out to buy MS-DOS." – Microsoft Senior Vice President Brad Silverberg

But anyway, NEC did something similar with its releases of MS-DOS between versions 3.3 and 5.0H for the PC-9800 series computers. It performed the aforementioned "Epson check," where it checks the computer's boot ROM and possibly others(?) for an NEC copyright string. If not found, it sends the PC into a reboot loop.

This is similar to the Sega "Trademark Security System" or Nintendo's Game Boy boot logo lockout (where the nintendo logo needs to be included in the cartridge ROM to proceed). Sega v. Accolade made such trademark based lockouts unenforceable. I guess they didn't buy their argument, which I would phrase as follows:

"Hey! You copied our proprietary string of characters that we deliberately used to lock you out and control our monopoly over a market! THAT'S COPYRIGHT VIOLATION! MODS! BAN THIS EVIL COMPANY FROM DOING BUSINESS IN OUR FREE MARKET THAT ONLY WE ARE ALLOWED TO COMPETE IN!!!"  – Sega, NEC, Nintendo, and every other entity that perverts the original intended purpose of copyright laws for an unfair advantage

Since the purpose of copyright law isn't to act as de facto patents, Sega was told they couldn't do that and use it to lock out unlicensed developers if these sorts of small bits of data were needed in order to achieve interoperability and allow others to compete on a platform. This was deemed as fair use. I do not think Japan itself ever had such a ruling... I may be wrong on that. Maybe they have by now, but given the abysmal state of copyright law there I'd assume not.

Identifying an "Epson Check"

In every case I've seen so far, "Epson Checks" have made the computer reboot during the booting process, putting it into a boot loop. If your game or other software does this during startup, it is likely an Epson Check. If it randomly reboots later on, then it may or may not be an Epson check.

According to the manual that came with Epson's Software Installation Package (which I did find), it resets just after the DOS copyright message shows up. Their manual states that some NEC board drivers also do this.

Patching the "Epson Check"

First off, Epson had its own versions of MS-DOS that did not have a check to begin with. The Epson check would exist if you tried to install NEC's DOS, or if a game or other software had a copy of NEC MS-DOS on its floppy disk. NEC's N88 Disk-BASIC also suffers from this check, but Epson released its own version of Disk BASIC that did not.

In any case, Epson created a "Software Installation Program (SIP)," which took NEC's DOS files and patched the copyright check so that it would pass on their systems. If this were in the US, I'm sure that NEC would argue that it was an unauthorized "derivative work" and go after them that way, but it seems that such a technique was considered fine inside Japan, at least at that time. Even though it sounds pretty much like how ROM hacks are made.

I haven't found a copy of the SIP, but there is a free (as in "Free Beer," not "Freedom") program for DOS that accomplishes the same thing called DISPELL. It used to be available on, but appears to have been erased in the last couple years after being online for a decade or more. Its page is archived here, or more directly can be downloaded here: dspl113.lzh.

If I remember correctly, the way I used it was first booting into DOS 6.2 (in version 6.2, NEC removed the "Epson Check"). I then inserted my floppy with a different version of NEC DOS (such as 3.3 or 5.x) on it, and ran:

> DISPELL.EXE /A <drive letter>:

This was enough to get a bootable DOS 3.3 floppy which I then used to launch Popful Mail, since Popful mail refuses to run on DOS 5 or 6. I think it's also possible to run DISPELL and tell it to patch just individual files, which might be preferable if you encounter a game that comes with DOS on it which seems to just go through a reboot loop constantly. In that case, you'd just want to provide the file names of the dos files on the disk. Be sure you also run dir /a to see any possible hidden files! And make a backup before you run the patcher.

I don't actually know what the /A parameter in DISPELL's case does. I didn't bother to translate it yet. If it were open sourced, I would have made a translated English patch for you guys. :(

It may still be possible to make a translation patch like that with just a binary to work with, but I don't know if I feel motivated enough to try to cram the english text into the pre-allocated space for a Japanese string (or else changing the pointers everywhere in the program). But for now, there seems to be a guide in Japanese here that might help (it has pictures).

To open the archive, LZH files can be opened in 7-zip, but there's also LZH (or is the program name LHA?) for the PC-98 if you want to unpack it there. I forget if it's compatible with the LHA files that the Amiga crowd often will use for distributing files. Also, Windows XP and higher should be able to open it just like zip files, albeit in Japanese releases only.

Regardless, by the time of 6.2, this "Epson check" had been had been removed, and NEC's version of MS-DOS 6.2 works fine on Epson computers with no modifications needed.

The Epson version of DOS seems to have a few nice extras sprinkled in, like a way to change the console colors at boot-up and a a fancy boot splash screen.

Without access to an NEC machine, it's hard to know if the few problems I've had are compatibility issues or not, but when my friend with the NEC-brand computers has time I'll ask her to try running some of my software and we'll see. But I can affirm that pretty much everything works; just some of the older software has some glitches which to me seems consistent with my expectations. My unit has enhanced graphical capabilities compared to early or mid-80's models, and I suspect that my problems are simply a result of the upgraded hardware and that mine is in fact "bug-compatible" with the 486-class NEC computers.

There are also some ways that it might be considered to be more compatible than NEC's from its era. Check this out.

The front panel of an Epson PC-486GR, containing a
                    high/normal resolution switch, a high/medium/low CPU speed                    switch, a volume dial, and four DIP switches.
A three-speed hardware "turbo switch!" You can change it at any time.

To my knowledge, no NEC PC-98s ever had a turbo button or physical switch, although some could be configured upon boot or internally with DIP switches. I can change the speed at any time, and have already gotten great use out of this feature.


Bonus: Floppy Disk Drive Terminal Mode

Some of Epson's computers seem to have one additional awesome feature which I was not aware of when I bought mine: apparently, you can use one as an external floppy drive bay for another PC. I first discovered this about them about a month after getting mine while reading through a Japanese message board thread archive. You can even use one of the supported Epson PC models as an external drive for an NEC PC-9801. The one limitation appears to be that only 1.2MB HD disks are supported in this mode (not single density, DD, or 1.44MB HD disks). Thankfully, just about everything I care about apart from ys is on HD media anyway. This feature seems to be endemic to Epson's PC-98 compatibles; this mode does not exist on any NEC models to my knowledge.

Given the prices of Epson PC's compared to external floppy drives, I am seriously considering getting another Epson at some point just for filling this role. Supported models (or at least some of them) seem to be:

It appears that soft DIP switches 2-7 and 2-4 might need to be changed, but I am having trouble deciphering what their values should be for correct operation. If the software configurator lets you flip both, then both. Otherwise, I would try just setting switch 2-4 first and seeing what happens. I think 2-7 is only needed if your system has three internal floppy disk drives. Mine (regrettably) does not have the 5.25" drive.

2-4 is the "FDD terminal mode" switch on my PC-486GR, as seen below.

BIOS setting screen on Epson PC-486GR. Switch 2-4, the FDD terminal mode switch, is highlighted in green.
To access the BIOS settings, hold the 'HELP' key while powering on or resetting.
Some earlier systems have physical switches or different key combinations instead. Try Ctrl+Graph while powering on.

The last thing about this terminal mode to note is that you can use either a real 'external FDD' cable or a standard(ish) style 50-pin SCSI "Centronics" cable for the physical connection between the two computers.


Laptop Features

You may recall that I said in the "red flags" section that no PC-98 laptops without a window accelerator chip built-in have FM sound. this seems to definitely be true, from the documentation I have seen, but only because I specified that "NEC never made any."

Because guess what?

Epson did make (some of) them.

Due to Epson's "upgradeability" as a marketing feature, it looks like it was made possible to swap one screen for another after buying if you wanted an upgrade; due to this, giving model numbers is kind of meaningless, but if you start with the 1993 models here you will see the ones that came with color screens in "stock" configuration.

However, you should be warned that many if not practically all of them no longer have functioning screens, according to others. They seem prone to dissolving into some strong-smelling vinegar-like substance with age. I am not sure how feasible it would be to replace the LCD with something newer. But I do believe that it might be possible to hijack the external RGB output from the back of it and feed it back in, if you were dedicated and could find a tiny panel that would accept its resolution. I have not seen evidence of people doing this (although I did not look particularly hard for such evidence either).

They should be usable as desktop machines plugged into an external screen, but why not just get a desktop with actual C-bus card support at that point?

I love the idea of the laptops. And the looks. I'm just not sure which if any of them are not prone to dissolving their own screens and haven't spent quite enough time researching them. If you are certain that your screens won't decay and you have a choice between a TFT and an STN panel, take a TFT. Unless you like and feel nostalgic for how blurry early color LCD's were (and for the really bad viewing angles and contrast dials). I think they're kind of neat; my thinkpad 350 has an STN panel.

It may be worth noting that it appears at least some laptops can have an expansion box plugged in containing multiple C-bus slots. So if you want to set up a laptop as a desktop, this may actually be feasible. I don't know what those parts cost now, however.


Things I Looked for When Purchasing

A lot of this section will likely be common sense, but I still think that that common sense is only 'common' if you already happen to know a bit about how these computers are put together. So perhaps not as much to a westerner like myself. If I sound like I'm babying you, that is not my intent; I just would rather say too much than not enough.

While you can't prepare for everything, here's some points to keep in mind.

"Junk" listings

Lots of japanese sellers list PC-98's as "junk." This may or may not be actually broken. Lots of the time, if something can't be tested, or is in less than stellar condition, it will be listed as junk. You may be able to get a good deal on something like this. My friend got at least two or three of their PC-98's as "junk."

I've gotten multiple Famicoms listed as "junk" over the years, and all have worked except one - and on that one, it worked after i cleaned some corrosion off of the pin connector.


I personally try to avoid rusty listings, but if the corrosion is minimal and confined to, say, the expansion slot covers on the back, then it probably was just stored in a somewhat humid environment for a long time. It's probably fine inside. But your eyes can be the judge. Super rusty listings should probably be avoided unless you have very good reasons to be interested in them (like accelerator boards, cards, and so on).

A lot of PC-98 listings seem to have some rust on them. three of four of my friend's have some rust on them, an they all worked when they arrived. My Epson was spotless, however.

Original boxes

If something still has its original box, that probably will serve as the ideal shipping container for it. It's probably the best way to buy a CRT, and I'd say things with hard drives especially are much more likely to survive shipping if in their original containers.

Also, anecdotally, I find that people who keep boxes tend to keep their stuff in nice shape.

Cards present in back of computer

If a computer has cards plugged into it, then those are cards you likely won't need to buy separately later! It also means the computer is less likely to have been gutted/parted out to maximize profits, and probably still contains whatever internal upgrades it may have had (if any).

Missing slot covers

If a computer has multiple missing card slot covers on the back, it's a pretty solid sign that the seller has removed cards that it used to have in order to sell separately. Although I suppose it's also possible the original owner just moved the cards to their new PC-98 if they replaced it at some point.

I try to discourage sellers from doing this kind of thing, so I personally try to avoid such listings.

Confirmation of operation

Obviously, it is ideal if the seller can confirm that the PC you are buying is still fully functional. But you can often get better deals on stuff where it has not been. Usually, in my experience, 'unconfirmed' operation genuinely is just that, rather than a CYA cop-out by the seller trying to avoid returns and pushing known broken goods.

My monitor was tested to power on but the seller didn't have anything to connect to it to confirm that it worked. They said they suspected it was fine because the screen 'turned white' (or something like that) when powered on. Indeed, when I got it, it turned on just fine.


If buying a monitor, some of them have detachable video cables. Make sure you get one with the cable, or that you can find one from somewhere else! The same is true for other things; if you can get it with a power cord, or with the little pass through video cable some video cards use, and so on, then it is more likely to be the ones originally coupled with the system and evidence it has not been parted out.


You'll almost definitely want a mouse, and you certainly need a keyboard. If you can get your PC with one or both of those included, that's stuff you don't have to buy separately later. My Epson came with its original keyboard, although I eventually bought a 9801V board after my friend talked about how nice hers felt. I don't regret it, but if you're trying to save some money, keyboards are kind of bulky to ship so you'll definitely save on shipping if your PC comes with one.

Game controllers can also be a good thing to look for; apart from being generally useful, I'd suspect stuff that comes with game controllers is more likely to have been upgraded internally from stock configuration!


If your prospective PC model does not have "86 sound" built in (YM2608 chip), then you should see if any of the ones for sale have a PC-9801-86 card (or equivalent) in them, still. I doubt you will have much success, given what those go for online, but if you can find it it'd be something you don't end up shelling out for later. Likewise, a SCSI controller (for computers without IDE) is a huge bonus. So are MIDI interface cards. If you're buying a really old model, you may need a bus mouse card as well; those can be hard to come by, so if you can find a PC that still has one in it, that's perfect. Even a "26 sound" card is a huge improvement over not having FM at all, since a lot of stuff still did support 26 sound pretty late on. If you are looking at models that don't have 26 sound integrated, those cards are also handy.

Finally, it appears there are C-bus cards out there that just contain RAM, which can be used to upgrade the memory of a system. If your PC has a special slot for RAM upgrades, you should use that instead (it might be faster or allow for larger ram upgrades), but if not, then more RAM is nearly always better than less. I think you will mostly find those in 80's era PC-98's.

Modem cards are pretty useless, in my opinion, but maybe someone needs one of those? - They are a pretty common sight inside PC's for sale.

Ethernet cards are handy for connecting other computers to your PC-98 or transferring files. I don't have one of these, but if you are looking you should try to find one with an "AUI" connector (15 pin D-Sub), or even better with a modern RJ45 ethernet connector for twisted pair. Many ethernet cards you will see just have BNC connectors on the back. These should be avoided unless you already have an adapter to convert that to twisted pair, or if you are only connecting to other vintage computers that use BNC coaxial ethernet. The adapters to twisted pair from BNC are very expensive, last I checked; AUI to twisted pair was easier to find and cheaper. Cards with both AUI and BNC connectors will be fine, too.

Original Documentation/Software

Mine came with neither documentation nor software, unfortunately - but if you see a listing that does, it might be worth it, especially if you're worried about keeping your software licensing kosher, since it's one less thing to need to buy separately. If you live in a country where no one cares about people copying 30-40 year old software that hasn't been available to buy for decades, then maybe this isn't a concern for you.

The documentation is still a huge blessing, though, because Japan is one of those countries where the public has been made terrified of the consequences of sharing out-of-print documentation or software. This means basically any documentation you find online will be a secondary source that at one point had access to a primary source. Obviously, this is far from ideal for a hobbyist. But it's sometimes good enough. There are a few exceptions I've found on western sites like the Internet Archive, where I was able to find scans of documentation for my Logitec SCSI controller card.

Drivers might be another huge road block. Until around 2016, it looks like you could still get a lot of documentation and drivers from Epson's site, but that seems to not be the case anymore. I was able to find drivers for my I-O Data graphics card on I-O Data's website, but this was the exception to the rule. And in that instance, there was no documentation available for download, so I had to look elsewhere to figure out what the DIP switches on it did.


Surprises Upon Arrival

You can only prepare for so much. Not all sellers necessarily can be expected to think to or know how to open up the case of the PC, for example, or even do something basic, like taking a good picture of the back of the computer where all the cards and ports are (and where the model sticker usually is).

In my case, there were several pleasant surprises inside.

My Epson PC-486GR with the case opened, showing extra RAM
                    board and CPU accelerator (486 DX4)
That blower fan is definitely not stock. The RAM card (right) isn't, either.
I wasn't expecting any of these bonuses!

My PC-486GR was bought with a description basically equating to "it worked when it was stored a long time ago." No other details were given as to the particulars, and only exterior pictures were taken.

I've made sure to back up the Mercari listing I bought for posterity:

When I opened it, there was more than anticipated to be happy about in there. Namely, the badge on the front plate of the computer (which is an Epson factory upgrade sticker proclaiming the presence of a 50MHz 486DX2 inside) was a lie... in a pretty good way. It actually had a 75MHz 486DX4 inside! Epson never offered a DX4 upgrade for this computer, from what I can tell; this accelerator board is from a company called "Asset Core" and it appears it may not have been marketed for very long. There are few pictures or bits of documentation of my specific accelerator on the web that I have been able to find.

This makes it run a wee bit fast for some older titles, even on the slowest clock speed option. Removing the 486DX4 made my computer fall back to the 25MHz 486SX soldered to the CPU card, but I've not been able to find a jumper as of yet to allow me to more easily disable the DX4. If I could find one, I could attach the jumper to a toggle switch on the back of the case to easily switch between CPU's (at boot time). As it is, I'm considering looking for another 486GR just for that reason. -_-

The CPU card additionally has both RAM slots filled. I think that supplies maybe 4 or 8 megabytes.

There's also a Buffalo ERB-4000 RAM board in there; it has 4MB on-board and two empty slots that I could put sticks in if Epson-type RAM were not unobtainium.

More generally, here's some things (a non-exhaustive list) to look for when you open your machine.

How much RAM?

The seller might not mention how much RAM it has. Hopefully, it has at least some, because PC-98 RAM (NEC PC-98 RAM) in general is not a standard pinout.

For NEC-made computers, It can actually cause damage to the RAM and/or computer if you try to plug a standard JEDEC-compliant SIMM RAM stick into it (like the rest of the world used at the time), since the ground and power pins are not in the expected locations.

The situation is a little better with the Epson models, where a JEDEC SIMM ram stick at least shares the same power pins, but JEDEC still won't work in an Epson due to different data and/or address lines.

Unfortunately, again, Japan is xenophobic and only lets Japanese citizens get access to the National Diet Library, which is what at least least one person who wrote instructions on converting standard JEDEC RAM for use in Epsons tells you to do.

Wyatt Cheng (the Dark Wyatt) at BlizzCon 2018, where
                    he famously said "Do you guys not have phones?"
                    to an irritated audience after announcing Diablo Immortal
                    (a phone game) to a crowd of PC gamers.
"Do you guys not have Japanese citizenship?"
[meme source]

On a side note, I would claim that allowing digital access to foreigners would only promote cross cultural understanding and cost the Japanese government next to nothing, since it is the ultimate arbiter of copyright law. But everyone is seemingly terrified of copyright laws on decades-old newspapers and magazines. Not to say that copyright as a concept is inherently bad/wrong; that's another debate I don't want to get into (although it is fun to banter about). But I think it is inarguably harmful to us in this specific case, and the subject matter is no longer commercially relevant in the slightest and there aren't reprintings being made to sell, to my knowledge.

Anyway, borders are dumb and arbitrary, promote an "us and them" mentality, and generally cause more harm than good. Thank you for coming to my TED talk.


Back on topic, obviously I can't "just become Japanese, lol" and magically get legal access to that document without physically travelling across half the globe to the National Diet and then potentially having to yank a random Japanese citizen off the streets to get the paper on my behalf. So I'm not going to do that to get the pinout of some RAM.

If anyone with access to a copy of pages 370 to 374 of the July 1997 issue of Transistor Technology can summarise the details for me, though, you'd be doing the world a great service.

Thankfully after hours of searching I was able to find a pinout for Epson SIMM ram. No thanks to that other person. Where was I going with this? - oh, right. It's possible that someone took the RAM out of your PC. I haven't seen this happen yet, but with a "junk" listing it'd be only too easy to do it and sell the RAM separately. Maybe if that's the case, you can modify a JEDEC stick to fit an Epson PC-98 clone by cutting traces and running wires.


Expansion Cards

Hard Drive Controllers

My PC does not have an IDE or SCSI controller built in, although some variants of it did come with one. There's an unused card edge slot in the case that can be hooked to a proprietary Epson card, which I believe uses SCSI and also houses a hard drive in a metal cage alongside it. I didn't see one on Yahoo Auctions, but did see that the cards have sold on there once in a while in the past. It might actually be a SASI card (pre-SCSI but basically compatible); I have read conflicting reports on that subject.

The lack of that card is not a deal-breaker, because there's also C-Bus, which is the also-proprietary, but-at-least-publicly-documented slot NEC put on the PC-98 series for end-user expansions. C-Bus SCSI controllers exist and can be used to boot a hard drive, even on computers where a proprietary hard drive interface is also provided. Mine came with one, although I had trouble making it work. I have a feeling it was a termination issue, since it looks to only have passive termination on it.

If you want to get a SCSI C-bus card, it seems that it would be best to get one that can be compatible with the PC-9801-55 card (which appears to be is the 'standard' that most or all bootable SCSI controllers seem to mimic to some degree).

There's a fair bit of configuration that many cards require to be done via DIP switches (if you can get a later era SCSI-2 card, you are more likely to be able to do software configuration than with older ones). I sort of understand this, since the main thing to do is ensure that no cards have overlapping addresses or interrupts, but sometimes the finer points elude me. It would be a good idea to take a picture of any cards you get before you start messing with the switches so you can restore to the configuration it came to you in.

One interesting thing to note about these cards that I have not seen mentioned in the English speaking world yet is that the little plastic tab on some cards which presses a switch next to the slot to indicate that the card should be treated as a 24-bit addressable card instead of a 20-bit addressable one. If I understand correctly.

(Picture of three C-bus cards; two SCSI controllers and one graphics card)
Back to front: I.O. Data GA-1024A-2 (graphics card), TEAC IF-55TB (SCSI controller), Logitec LHA-301 (SCSI controller).
Note the plastic doohickey on two of these cards. This presses down a switch that is present in some PC-98 models.

Apparently some later 24-bit addressable cards don't have the button presser anymore, and some later 9821s don't have the switch installed on all slots but just assume a card is 24-bit addressable if it is present. I swapped a 'button presser' onto the card closest to the camera from the one in the middle and behavior did not seem to change, but the card closest to the camera did already have a spot for me to screw the lever thing into it, so it was clearly designed with the intent of using one at some point.

Don't peel those stickers off the brown chips, by the way. Those cover up EPROM (Erasable Programmable Read-Only Memory) quartz windows, and if exposed to the right light frequencies (somewhere in the ultraviolet range) the chip will eventually be erased and the card won't operate properly. If you happen to have an EPROM programmer and the correct pin adapters, it'd be really great of you to dump the cards' ROMs and share them, too, because they could lose their data naturally even without light exposure at some point and need reprogramming. I sort of doubt the manufacturers care enough or even have the files (if they still exist) to help you out. Once the chips have lost their marbles, it's too late, unless someone's made a backup and can re-program them.

I'll give a brief description of what some cards do, now.


Logitec LHA-301 SCSI Controller:
This card is the SCSI card I actually use with my system. I had to buy it separately; the PC did not come with this card from the previous owner. They had the TEAC IF-55TB installed, which I could not get to work reliably, so I replaced it.

(Picture of a so-called mini centronics female connector for SCSI drives)
Both of my SCSI controllers have a 50 pin "mini centronics" connector like this.
I see some Japanese people call it "half amphenol" as well, and Wikipedia calls it an 'HPCN50.'

It uses a "half-sized amphenol" (mini-centronics) connector, which is not a common SCSI connector here in the States but which seems to have been rather popular with Japanese manufacturers instead of the "HD50" miniaturized D-sub that most stuff seems to have used here. The LHA-301A uses a more common (in the west) HD50 connector, but I did not see one for sale, and after reading descriptions of various SCSI controller options online the 301 and 301A seemed like some of my best bets. They even support "PnP" ("plug-n-play") in Windows, and support up through Windows 2000. If I upgrade the BIOS ROM (not sure how exactly to do that) from 1.05 to 1.07, it seemingly can support up to 8GB SCSI drives. LHA-301 also supports three data transfer methods for interacting with the host system: PIO (the simplest, where the CPU is involved with every byte read in), DMA (direct memory access, which bypasses the CPU and writes directly to addresses in RAM so the CPU can work on other things), and SMIT (I have absolutely no idea what this is, but it seems to be the consensus of Japanese documentation I've found that it's faster than both DMA and PIO). I have mine configured for DMA right now and haven't had issues. I think there may be a DOS driver I need to install to actually make use of it, but I haven't done so, since I haven't felt too throttled by disk I/O yet and am just glad it's working so stably right now.

I had to switch it out of "MO" (magneto-optical?) mode in order to make the DOS installer see and initialize it properly - I guess maybe a past owner was using it with a magneto-optical drive. The 130mm ones seem pretty cool. But I'm not getting one right now! - I've spent enough on this thing as it is!

This card has a software-based configurator (accessed by holding ctrl+grph+L during boot) instead of DIP switches; I think it's really nifty. It also actually works for me (as opposed to the IF-55TB), which is also pretty nifty.

One thing worth noting about the LHA-301 is that it doesn't seem to work with older, mechanical PC-98 keyboards (like PC-9801V boards). I believe this is because the 9801V board requires the PC to send a "READY" signal to the keyboard before the board will send any key events to the host computer. Later boards apparently do not require this. I could not even enter the configuration screen with the 9801V board, and had to switch to my rubber dome Epson to do so. There is one generation of PC-9801 mechanical keyboard after the 9801V series, so I cannot confirm or deny if those work. The difference there is that the lock keys don't mechanically latch downwards ('alternate action') when engaged. They also have the extra 'function keys' that are lacking on the 9801V board. There is a chance that these later mechanical keyboards will work, but I can only guarantee that my 1992 rubber dome Epson board (and probably rubber dome NEC boards from around then onwards) can be used to configure the LHA-301.

So, if you don't want to have two keyboards sitting around, you may need to avoid the LHA-301, accept that you will be using a mushy rubber dome board, or maybe try that final generation of mechanical boards with the extra function keys and non-latching lock keys.

This is the only time I have found a problem with using the 9801V board - Everything else I have tried works fine with it. I'm just glad I already had successfully configured it with the Epson board, or I would have probably not recognized that the keyboard was the problem.

From what I can see, the difference might be that the 55TB doesn't seem to have a voltage regulator on board, which is a prerequisite for active SCSI bus termination (the better kind). If I have an active terminator on one end and a passive resistor pack terminator on the other, that might explain why it behaves erratically.

(Picture of a so-called mini centronics male connector for SCSI drives, with an HD50 male SCSI terminator on top of it for visual comparison)
Male mini-centronics SCSI connector, with male HD50 for comparison.
Apparently, the pin arrangement/electrical wiring is identical between the two.

There's one thing it can't do, which is the PC-98's "Hi-Res" mode, which requires things to be at different addresses. I don't think this mode ever got much use, and later Windows-era machines had a different, incompatible solution for higher-resolution display. Since I don't know what I'd use it for, it doesn't bother me yet.

Sound Cards

There are a few different kinds of sound cards available for the PC-98 series. I currently only have a dead PC-9801-86 that needs new capacitors and a working MPU-PC98II; 26 sound is integrated into my PC's main board.

86 Sound:
If you are lucky, your system will already have a PC-9801-86 compatible sound chip (YM2608, or OPNA), or even the full PC-9801-86 C-Bus board installed. There are also a handful of clones of the PC-9801-86 that exist, but they don't seem especially common online. The -86 board is common, but also expensive. If you can, I'd suggest looking for a computer with a built-in "86 sound" chip. On With98 (see links), these are represented with something like "YM2608," "86 sound," or mentions of PCM or ADPCM capability. I think it was introduced alongside the PC-9821 series, or perhaps very shortly thereafter. Most 9821 models should have it, I think.

An "86 sound" compatible system will get you PCM audio support, which is a massive upgrade that allows for things like voice acting, or things like sound effects in Windows 3.1 (if you're into that). It also gets you stereo FM synthesis sound and PCM recording capabilities. In the long term, it's a nice thing to have.

The 86 sound card (i.e., not integrated onto motherboard) has a single DE9 (often mistakenly called DB9) connector for a joystick using a variant/extension of the basic Atari (2600) joystick pinout. For at least one of the two fire buttons, it may be usable with a Sega Master System or a Mega Drive pad as well. To get multiple fire buttons working with non-MSX pads, some rewiring or adapters may be required. I talk about this more in the "joysticks" section, later down on the page.

If you want both fire buttons to work on your joystick/gamepad, then it needs to rewire/map the second fire button to pin 7 (first one is on pin 6). It follows the "MSX" joystick pinout. Sega pads put the second fire button on pin 9, so you'll need to make an adapter or rewire the controller. I've made a adapters for some different kinds of joysticks: a modified TAC-2 joystick with two distinct fire buttons (fire 2 on pin 5, like the Comrex), a Comrex Commander joystick (fire 2 on pin 5 from the factory), and some Sega gamepads (fire 2 on pin 9). You should also make especially sure when doing this that 5 volts and ground (if present) are mapped correctly. See the "Joysticks/Gamepads" section for some more information on hooking joysticks up to a PC-98.

You will likely need to disable your integrated 26 or 86 sound chip in your BIOS or with DIP switches for the one on the card to function.


26 Sound:
An earlier sound card, the PC-9801-26 (or PC-9801-26K), will get you mono FM synthesis sound and no PCM playback. It is based on the YM2203C OPN chip. My Epson PC-486GR has one of these integrated into it, as do many other early 90's and perhaps late 80's PC-98 models. If you're on a budget, be reassured that most games I have tried support it, and especially for the earlier DOS games (from the 80's) that I am most interested in it's all you will need. It does not however have PCM, and it is mono sound only.

The PC-9801-26K has more clones available than the -86 seems to. It's also a fair deal cheaper to find a 26K card.

It has two DE9 (often mistakenly called DB9) connectors for joysticks in the "Atari joystick" button configuration (actually, the MSX variant thereof). This means it can be partially used with Sega Master System pads, or possibly Mega Drive pads. If you make a wiring adapter, they can fully work with Sega controllers or any other 'parallel type' western joystick. See the above "86 sound" section for a brief run-down on the wiring.

Integrated 26 sound computers may not have a joystick port. Unlike with the "86 sound" integrated models, I am not sure if an adapter can be made to repurpose the mouse port on the 26 sound models. For this reason, even if you don't want 86 sound, you may still want to at least buy a 'dedicated' PC-9801-26 sound card, which is cheaper than an 86 by far. See the "Joysticks/Gamepads" section for some more information on hooking joysticks up to a PC-98 system.

You will likely need to disable your integrated 26 sound chip in your BIOS or with DIP switches for the one on the card to function.


Sound Blaster:
There is a Sound Blaster card for the PC-98, using an OPL3 chip and very much analogous to the ISA sound blaster 16's in IBM compatibles. I don't have a clue what software uses it, but there you have it. It does exist. It also has IBM-style joystick connectors ("gameport connectors"). Neither I nor my friend currently have any of these cards.


Some stuff, especially later in the PC-98's lifetime, seems to adopt MIDI sound. I am not aware of too many (if any) cards that perform on-board MIDI synthesis, so you will likely need an external synthesizer. One cheapish way to do that, once you have a MIDI card, would be to get a good quality USB MIDI adapter for a modern PC and run a software MIDI synth like timidity on it, and then connect a MIDI cable between the PC-98 and the modern PC. If you pick the right soundfont, that's enough to get you basically a Roland Sound Canvas. A lot of games use "GS" (Roland's General MIDI extension) or General MIDI instrument mappings, so that should get you a long way. Some games also use the Roland MT-32, which is not GS compatible. You could perhaps use MUNT (which emulates the MT-32 pretty well) for this, if you can legally obtain the ROM chips and dump them. That way, you just need to connect your PC-98 to a modern PC and have the modern PC perform the MIDI synthesis for you.

You could also hunt down a physical Roland Sound Canvas (SC-55mkII and SC-88 seem to be popular options) for the GS games. For the MT-32, an actual MT-32 is ideal; a D-110 might also work, but the sounds will be different (arguably, the D-110 has better samples - but it will not represent what the games were actually designed to sound like, even if the instrument ID's mostly match up). The D-110 is also huge by comparison to an MT-32, since the D-110 is 19" rack mounted equipment.

(Picture of a Roland SC-55K synth on top of a Roland MT-32 synth.)
Roland MT-32 and SC-55K. The Sound Canvas and MT-32 seem to be the primary MIDI synthesizers used with the PC-98 series.
I'm going to have to find a better way to stack these with my monitor.


Roland Sound Canvas:
I just recently got a Roland SC-55K, which is based on the SC-55mkii but lacks a screen and most of the buttons of the actual SC-55mkii. It's a unit meant for karaoke, is Japan-exclusive, and is also basically an enhanced version of the SC-55ST. The 55ST, unlike the SC-55K, has no MIDI thru or MIDI out ports to speak of. So if you're choosing between a 55ST and a 55K, I'd suggest the 55K. It's just a 55ST, but with more I/O. For the non-Karaoke features, you can just use the SC-55ST manual for directions and it'll get you where you need to go, since the 55ST is a strict subset of the 55K's functionality.

Don't be tempted into thinking you can just use your PC's serial port as a MIDI interface; most software doesn't seem to allow doing this, even though the 55mkII, 55ST, and 55K all support MIDI over RS232. Things really expect you to have an MPU interface, unfortunately for your wallet.

If you get a 55ST or 55K, and your software does support MIDI over RS232 on a PC-98, you want to use the "PC-1" position for the switch on the back. The 55K's Japanese manual says that the "PC-1" position is for the "PC-9800 series," whereas the English manual for the 55ST omits that and just mentions in a note that "PC-1" is for a 31.25Kbps connection. Otherwise, it basically glosses over the existance of the "PC-1" setting and emphasizes the use of "PC-2" for IBM compatibles (PC/AT class).

The SC-55 and family are GS MIDI synths; if a game asks you to choose between "GS" and some other sound formats (perhaps "26", "86", and "MT"), "GS" pretty much means the Sound Canvas series in this context.

I've run my 55K with the original Roland 100V-in power brick straight from a wall outlet (around 120V) without issue, but I typically use my stepdown transformer to be safe. See the relevant section about powering Japanese domestic electronics.

For the record, the SC-55K,and presumably the SC-55mkii, ask for a 9 volt DC, tip/center-negative power connection. This is the same as an MT-32, a Famicom, a Super Famicom/European SNES, or a Sega Master System, and almost the same as a Sega Genesis (model I only). So if you don't want/can't use a stepdown transformer, or weren't given the original power brick with your Japanese-imported unit, you can use any of the above power bricks as a substitute. The extra one volt or so of the Genesis power brick will be burned off as extra heat by the 7805 voltage regulator that the Sound Canvas uses. You could probably even use a 12v center negative brick and it'd work. If you encounter problems with this, the 12 volts might be overheating the regulator. Let it cool down and use a lower voltage brick.

You can also get a new power brick for it; I've had luck with the Triad Magnetics WSU090-1300-R power adapter, which I've been buying through Digi-key. It can also be bought from Mouser - or even Console5, apparently. I typically don't use Console5, but maybe it's worth it if there's some other old game console stuff you need. I've only once bought something from it, and that was for making my own Wii S-Video cord.

This isn't meant as a promotion for the Triad over any other supply; just as an easy option that is readily commercially available if someone doesn't want to do the legwork to figure out all the specs on their own. Anything that can deliver at least one watt at 9 volts DC, has a negative tip/positive shell polarity arrangement, uses an approximately 2.1mm x 5.5mm x 11mm plug, and accepts your local voltage as an input should work.

Note that the '-R' at the end of the product model name is important. The non-'-R' version of this supply is positive-tipped, and will quite possibly damage your hardware. So if you're looking for one on other sites like eBay or Amazon, make sure it's the '-R' version.


Roland MT-32:
I have also seen some software that supports the earlier Roland MT-32. Thankfully, I've had one of those for about five or six years now. I can't really recommend buying an MT-32 at today's market prices, though. I think there was a Raspberry Pi project I saw to emulate an MT-32 which looks much more affordable. And MUNT (the software MT-32 emulator people use) is getting pretty good. The only inaccuracy I've noted (I arrange music on my MT-32) are that sometimes my real (early revision) MT-32 drops notes that MUNT will play correctly - I have never felt that something felt wrong due to this extra polyphony. My early revision MT-32 also can't handle system exclusive messages in rapid succession like later revisions of the hardware (or MUNT) can. So in a lot of ways, I'd argue, MUNT is actually better than the real thing.

That won't make me stop loving my MT-32, but it is a reason that I don't think it's truly necessary to own one. If you can find a legal way to obtain the ROM chips, that should be enough. Maybe someone on ebay will sell the original chips harvested from dead hardware once in a while? I'd guess that that would count as owning a legitimate copy of the copyrighted information to make your own ROM dumps from. MUNT does require ROM dumps to work, unfortunately.

The MT-32 uses the same power input as the Sound Canvas SC-55. Read the section on the Sound Canvas for more information.


MPU Card:
Just having a synthesizer isn't enough. You also need a way to connect it to your computer! On IBM compatibles, one would initially have used a Roland MPU-401 box with MIF-IPC or MIF-IPC-A (compatible with faster computers) ISA card. On a PC-98 series computer, this would be an MPU-401 box and Roland MIF-PC98 card.

Later on, the MPU-401 was integrated into the interface card, eliminating the external box entirely. For an IBM compatible, this would be a Roland MPU-401AT ISA card; for the PC-98 there were the MPU-PC98 and MPU-PC98II cards. From what I gather (this may easily be wrong; this is information gathered from hearsay), the main difference between the MPU-PC98 and MPU-PC98II cards is that the 98II has DIP switches to change IRQ settings (a big deal!). Perhaps some bugs were also fixed; I can't find any concrete evidence on this front from a cursory search.

I bought an MPU-PC98II interface, which lets me eliminate the need for an expensive external box and also lets me change IRQ's. It may be argued that given the simplicity of the interface cards and availability of brand new cards for interfacing with the external MPU-401 boxes, I should have bought that version instead so I could share a single MPU-401 with IBM-compatibles. That's a fair point, except that currently my only working IBM compatible with externally facing ISA slots is an AT&T 6300 (8086-based) PC, which is quite a bit older than I'd want for music. My Pentium III Gateway has a single ISA slot, but it's not got an exposed bracket, strangely. And the Pentium III can probably(?) use MIDI out over a Sound Blaster Live! PCI card, anyway, which incorporates much of the MPU-401's functionality and cost me far less (as far as I can remember, it was free). I don't know if the "intelligent mode" of the MPU-401 is emulated there, though.

The "intelligent mode" of the MPU-401 uses an 8 track sequencer, sync and metronome outputs, and possibly other things. The alternative is the simpler "UART mode," where the MPU-401 basically acts like a dumb 31250 baud serial port. I don't know that I've personally ever had trouble, but it's something other people on the internet always are warning people about regarding USB adapters with old synths like the MT-32. Maybe my USB adapter has that 'intelligent mode?' - It's the Roland UM-One. Some of the other USB adapters I've tried are prone to dropping notes. Maybe that's why. I'm out of my element here. It appears that emulators like DOSBox and Neko Project 2 Kai support MPU-401 emulation in software (and thus should be usable with a dumb UART USB adapter).

I'm not aware of any hardware MPU cards that don't come from Roland for C-Bus, so maybe it's irrelevant to worry about intelligent mode MPU-401 support.

(Picture of a Roland MPU-PC98II MIDI interface card.)
My Roland MPU-PC98II MIDI/MPU-401 card. I have no clue what the buzzer's there for! - I don't think I've ever heard it go off. Perhaps it's for the metronome input.


Which Synth to Buy?:
If you are wanting to buy a MIDI module, but only one of them, and you don't have a huge amount of money to do so, I'd say the SC-55 or similar is a better purchase for a wider variety of games. If you do have a huge amount of money, get a CM-500 which contains both an MT-32 and a SC-55.

And if you have a truly enormous sum of money, and you want to thank me for writing this, I of course wouldn't say no to being offered a little of it. ;)

Of course, I also appreciate a written 'thank you,' even without monetary transactions. It's also a great motivator to keep writing if I know I'm helping people.



For the most part, using factory default settings, most stuff "just worked" for me.

However, my LHA-301 card wanted to be on INT0 (IRQ 3). This is the same IRQ my PC-9801-86 card wants to use by default. I suspect this was at least part of why Touhou 4 and 5 would hang my computer. The final IRQ's I chose for all my parts are as follows. For the sake of providing more information, I have also included the other IRQ's (including internal ones that don't really have much to do with the C-Bus). C-Bus IRQ's should be any that have an associated interrupt number.

Basically, when you use expansion cards, your goal should be to not have any IRQ's overlapping between different bits of your hardware. So if your sound card is on IRQ 3 (INT0), you should make sure none of your other cards use IRQ3 (INT0).

IRQ # Interrupt # Device Name PC-9821Ce2/Cs2
0 System timer (internal)
1 Keyboard (internal)
2 VSync/CRTV (internal)
3 INT0 PC-9801-86 (My sound card)
4 RS-232C (internal)
5 INT1 MPU-PC-98II (My MIDI card)
6 INT2
7 "Slave:" IRQ8-IRQ15
8 Printer (NEC V30 CPU models)
"Numeric Data Processor" (80286 CPU models)
9 INT3 Logitec LHA-301 (My SCSI card)
(Hard drive controllers, both SASI/SCSI and ATA)
"Hard Disk/CD-ROM Interface"
10 INT41 "640K Floppy Board Interface"
11 INT42 1MB Floppy Drive Controller (internal) "1M Side, 1.44MByte Interface"
12 INT5 "Sound Board"
13 INT6 Bus Mouse (by default) "Mouse Interface"
14 "Numeric Data Processor" (NEC V30 CPU models)
Unused (80286 CPU models)
15 (System timer?) (internal)
Bold: As configured in my system.
Italic: Systems usually (but not always) use this interrupt for this purpose if hardware is present.

You can find a more complete (and complicated) table in English here.

Note that the MPU-PC98II MIDI card defaults to using INT2, so I moved it to INT1 by changing a jumper. I discovered that Touhou 2 would not use my MIDI card otherwise, for some reason. I've seen some discussion online about how its MMD driver (its MIDI driver) has trouble/won't detect a MIDI card on IRQ #6. But for most other stuff, if you encounter weird issues - especially MIDI issues - try changing the interrupt back to INT2.


Things You Can Do While Your PC-98 is Being Shipped

So excited you can't sit still? Need to do something during the torturous wait for the day the huge expensive box arrives at your door?

Well, lucky you. There's a lot you still need to have ready besides the box itself.

Power Converters

At the risk of promoting FUD, I will point out/remind you that the Japanese power grid runs at 100 volts AC (at either 50 or 60 Hz). You shouldn't have to worry about frequency regardless of where you live, but if you aren't in Japan itself you may want to or need to invest in a step-down power transformer.

Japan's mains voltage is the lowest in the world, and it is the only country that uses this voltage. It just might be close enough to the US power grid's 110, 115, or 120 volts to work - seemingly, the number depends on who you ask, the specific year, and several other details. It seems that the standard in the US is now 120 volts, but that prior to sometime in the 1970's most regions used 110 to 115 volts. Regardless, we now use 120 volts, which is of course 20% higher than what the power supply in your PC-98 was designed and rated for use with.

Side Tangent: Power Supply Math (skip to end)

Now, if you're familiar with how power supplies work, forgive me for going on this tangent, but in case you aren't, here's the gist of it, and the reason for why it might work, if you make a lot of assumptions about how the power supply is designed.

Some terms related to power supplies to know about:

Now, based on those parts, maybe you can guess how an AC to DC power supply is typically put together for something like a computer. Just in case you don't quite see the picture yet, I can elaborate. Here's a (simplified) step-by-step of what happens in a power supply.

  1. Alternating current (AC) is fed into the power supply from the wall.
  2. A transformer (basically, a kind of wire coil) is used to bring the higher AC voltage down to a lower voltage, closer to what you are trying to supply power to.
    • For our purposes, let's say that we designed the transformer to take 100 volts AC in and output 10 volts AC (a 10-to-1 ratio of input to output voltage).
    • Remember: this same transformer, assuming it was beefy enough to handle the heat and voltages involved, would (I think) also reduce other input voltages by the same ratio. If fed 220 volts, it would output 22. If fed 120 volts, it would output 12.
  3. The lowered AC power output from the transformer is fed into the bridge rectifier to turn it into (pulsed) direct current.
  4. The pulsed DC output gets one or more filter capacitors put between the two power rails (ground and positive) to smooth out the pulses into a less fluctuating, more conventional/constant direct current.
    • Typically, there is still a little 'wobbling'/fluctuation of voltage after this step.
    • The smoothed DC is still prone to fluctuation based on changes in the input AC voltage, so we have to do one more thing to make it trustworthy.
    • With our 100V input, 10V output transformer, the smoothed DC is probably about 8 or 9 volts, rather than 10 - the diodes in the rectifier dropped some of the voltage.
  5. The smoothed DC is fed into a voltage regulator, which outputs a relatively constant/stable voltage, even under load.
    • Many voltage regulators have some minimum input voltage required to operate which is markedly higher than their desired output voltage.
      • For this reason, shaving as close as possible to the output voltage with the transformer itself without going below your target isn't a viable answer; the output voltage must be somewhat higher, which means that some amount of heat is inevitable.
      • The LM7805 is a very common linear regulator; it is used in the Atari 2600, NES, Master System, Mega Drive/Genesis, SNES, and probably loads of others. Many companies make LM7805's or clones thereof, and their individual specifications may vary slightly, but in general datasheets seem to say you should supply at least 7 or 7.5 volts DC for them to operate properly and output 5 volts DC.

So, given that information, and given that we designed a power supply to turn 100 volts AC into 5 volts DC, let's imagine how the voltage would change as we go through the steps when inputting 100VAC:

100V AC -> 5V DC (hypothetical) with 10:1 transformer

  1. Transformer: 100V AC -> 10V AC
  2. Bridge rectifier + smoothing capacitor: 10V AC -> 8.6V DC (rectifier diodes drop some voltage, let's say 1.4V)
  3. 7805 voltage regulator: 8.6V DC -> 5V DC (difference of 3.6 volts)

Given an appropriate cooling solution, the 7805 can handle some rather large (10 volts or more) voltage drops; the main problem is adequate cooling. The two things that make a linear regulator run hotter are input voltage and output current; output current (we assume) is rather steady. So what happens if you increase the input voltage to 120V?

120V AC -> 5V DC (hypothetical) with 10:1 transformer

  1. Transformer: 120V AC -> 12V AC
  2. Bridge rectifier + smoothing capacitor: 12V AC -> 10.6V DC (rectifier diodes drop some voltage; let's say 1.4V)
  3. 7805 voltage regulator: 10.6V DC -> 5V DC (difference of 5.6 volts)

So, the 100V -> 5V setup would (in this configuration) dissipate about 3.6 watts with a 1.0 amp load (wattage = voltage × current). The 120V one has a 5.6W drop; a difference of two watts. If I read the TI datasheet correctly, it seems like it expects a four degree celsius rise for a one amp increase, so perhaps it would run eight degrees celsius hotter? - this feels like a massive oversimplification. Someone who actually didn't flunk out of engineering school, please correct me!

End of Tangent

This might be fine, and if it is it would certainly save you some money if you live in a <=120V country. But your computer's power supply would at a minimum run hotter than it was expected to by the engineers who designed it, and at worst have a reduced service life, overheat, or cause some somewhat low-rated filter capacitor to pop (remember that electrolytic capacitors often have huge margins of error on them on the magnitude of 20%). I'm guessing that a respectable company like NEC would not have used the bare minimum capacitor ratings, but these caps are still old unless you replace them, and a nice Japanese-made step-down transformer can be had for $100 or less to remove some of the nervousness that I would have plugging it in directly.

I have successfully run a Roland SC-55K with its original Japanese 100V rated power brick directly on US wall power, but I still am using it with a stepdown now - after I realized that I'd just been using an incorrectly specified Japanese domestic wall wart. You guys in Europe are kind of lucky, in a way: it'd be a lot harder to accidentally plug a Japanese power cord/brick directly into your wall. Here in the states, it is quite easy to do absentmindedly.

I do recommend labelling your power cables on both ends - down by the plugs and up by where they plug into your equipment. I used blue painter's tape to make them stand out. This way, I am hopefully reminded that there is something special about the plug I'm holding if I ever need to rearrange the cables under my desk.

If your PSU happens to have text on the back stating that it is rated for at least your voltage, then ignore everything I just said. But my Epson at least only specifies 100V at 50 or 60 Hz.

If you are in Europe, you will almost certainly have to get a step-down transformer, unless there's some industrial PSU for PC-98's used with something like CNC machines that I'm unaware of and your machine came from somewhere like that rather than from Japan.

I went a little pricier with mine and bought a used Sanyo TSD-N11LU transformer, with a nice "capacity indicator" and a rating of 1100 Volt-Amps (not QUITE the same as saying 11 watts, in this case, apparently, but I don't know why that is. My guess is that it's something to do with how the transformer is actively changing the voltage and permissible current ) If your PC, monitor, and anything else Japanese that you are running off of your transformer totals less than the rated wattage, you should be fine. To be safe, I recommend going significantly higher than the minimum; things like hard drives draw a lot of power draw at spin-up, which might be fine for a short period of time, but I've seen stuff fail from excessive current draw when spinning up a bunch of disks before. I'd also just suggest trying not to stress your hardware, since it'll be expensive to ship. more of it if you break it - assuming you can even find exactly your computer or whatever it is you are trying to replace. It also provides future-proofing; part of my reason for going high was in case I ended up importing a CRT (which I did).

If you can find an isolation transformer, that's especially nice, since while heavy it means you don't have to worry about earth grounding it at the wall outlet.

Accessories that Use AC Adapters

For accessories for your PC-98, if they use a DC barrel jack, you may be better off if you get a new wall wart that is simply correctly specced for your mains voltage and desired output/plug size. I mentioned the correct AC adapter for the Roland MT-32 and SC-55 above, for instance. This way, you don't have to worry about getting a power strip or similar for your stepdown transformer. Most of the good ones (non-Chinese) don't have a ground prong on their outlets, so most US spec power taps won't (safely) be able to cut it. You might have to import a Japanese strip, or use a US "cheater plug" with a wire strapped to that metal contact underneath that runs to a ground point on the stepdown transformer.

If you want to get something new and of reasonably good quality, I'd suggest ordering on Digi-key or Mouser - or at least searching for part numbers by doing that and then buying what you find by narrowing down your search off of somewhere like ebay, or maybe your local hobby store, if your hobby shop will get stuff like that for you.

If your stuff comes with the original AC adapter, you can probably use it with your step-down transformer as well.

Using western 120/240V accessories with a 100V PC

Perhaps it's just on account of poor quality electronics in the housing, but if I have my external SCSI hard drive housing switched on prior to turning on my Epson, the epson comes up with a "VR Failure" error (which I assume means "Voltage Regulator"). When using a ZuluSCSI board in the housing, I don't have to connect the 120V AC cable to the housing since it's powered by the SCSI controller's "TERMPWR" (Termination Power). Doing this, I can sidestep the error. I can also simply turn on the PC prior to flipping on the power switch on the housing and then press reset on the PC, and that also works.

Why does this happen? I honestly don't know. I suspect it has something to do with the two devices not sharing a common earth ground, perhaps. Or maybe the power supply design inside my drive housing is of questionable quality? It's not a name branded thing, so that wouldn't be entirely surprising to me. But the output voltages are pretty much on the dot (checked with my Fluke 77 multimeter).

Obviously, something weird is going on, so if you come across problems like this, I'd suggest trying to avoid using those accessories, but I've yet to find that I've actually hurt anything by doing this. Maybe it's just that the disk drive is trying to provide termination power and that's messing something up with the power supply to the C-bus cards? It might not be 120V related at all.

In general, I think you'll probably be fine to use your domestic stuff with it, as long as nothing has a hot chassis (you have bigger problems if you have stuff with metal casing that does this; I don't think anything you'd want to use with a PC-98 would have a hot chassis construction, so it's not something to worry about). It can be a good way to save some money, if you can find domestic printers, scanners, serial terminals, external CD drives/external hard drives, and so on.

…Actually, my modern desktop PC (which runs on 120V) is hooked to my PC-98 via a null modem serial cable, and it doesn't give a voltage regulator error message, so it's probably just some peculiarity of my SCSI controller or drive housing or configuration.



Did your PC come with a mouse? If not, you need to get one for a lot of newer software.

First off, you can't use a serial mouse. Well, maybe you can, at least in Windows, but if you are trying to run DOS programs I don't know if there's any TSR or similar software to make a serial mouse work. I also would expect that even if there is some workaround like this (akin to CTMOUSE/Cutemouse in western DOS), no DOS programs for the PC-98 are going to be programmed with such drivers in mind and may cause resource conflicts. Basically, I wouldn't even try, and consider it a bad idea, given the relative ease with which you can get a fully-compatible mouse.

What you actually need to look for is commonly termed a "bus mouse." These mouses just send raw signals from the optical gate sensors on the X and Y axis rollers of a ball mouse over a wire back to the host computer, with no encoding like PS/2 mouses use. Pinouts varied, so not all things that could be arguably termed "bus mouses" will work, but anything made for IBM PC's probably will.

The term "bus mouse" refers to the fact that early PC's had no built in mouse port, and so the user had to get or make an ISA card and link the mouse up to the computer's ISA bus. When used outside of an IBM context, these mouses typically seem to be called something like "quadrature mouses" instead. The terms are largely interchangeable. Quadrature is a word to describe the four signals that a mouse will send out for ball movement (two infrared light sensors per axis).

Here's the run down on the things you might need.

Mouse Card (Older Systems Only)

Older PC-98's might not have a mouse port, and for those you'd need to find a "bus mouse" card, I believe. This only applies to the ones made before around 1985. This site claims the PC-9801, the 9801E, 9801F, and 9801M models are the ones that need a mouse card. I don't have a PC-98 that old, so I haven't looked too hard, but I did not see any mouse controller cards with a cursory search when I tried. They're out there, but they might be somewhat uncommon. I'd expect that the early "green eyed" microsoft mouses came with cards, so maybe look for those? - Obviously, you'll need the C-bus version (not the ISA version the US and other countries got). It might be ASCII or NEC branded instead of Microsoft.

You should note that most software that requires a mouse is probably new enough to need EGC, so these early PC-98 models will be pretty much useless in that capacity. The main reason to get a card would be for historical interest, I'd expect.

These early C-Bus mouse cards should use the 9-pin D-Subminiature connector as described in the following section. You can of course make an adapter to use the mini-DIN variant connector with one. I have reason to believe that the IBM-compatible version of the Microsoft "green eyed" mouse used the same connector, so if you get a card without a mouse, that might be an option for you that will save on shipping... but I see that someone recently bought one for $80 on ebay without a card, so it may be a smarter idea to just import some other PC-98 mouse from Japan or make an adapter (see the following section).

I've seen at least one NEC ad featuring the green eyed mouse, so it could be a period-correct part for an early PC-9801 model that needs a separate mouse card, if you're going for originality. Actually, it looks to me from a search like the model number for the original mouse bundle might be NEC's "PC-9871." It seems to include a Microsoft green eyed mouse. There were maybe other mouse interface boards released later… but the PC-9872R seems to be just a DE9 mouse without a card. So maybe not. The mouse port was integrated pretty early on; it seems like the only models that need a card are probably the original PC-9801, the 9801E* 9801F*, and 9801M* series. Later ones seem to have an integrated port. You should check that yourself before you take my word for it, but I believe this statement to be accurate.

Two Mouse Connectors

For later machines, you will probably have one of two possible connectors. The choices are a 9-pin D-Subminiature connector or a 9-pin mini-DIN connector. If you have the mini-DIN, it's the same pinout as a "Microsoft InPort" bus mouse for the US market, which is for mouses that connect via an ISA card. For this reason, searching ebay for a PC "bus mouse" can get you something electrically compatible with a PC-98. Just make sure it's not Apple Desktop Bus (a different thing entirely). If it uses the D-Sub connector, you will need to make or get an adapter. I think the adapter will have to come from Japan, since the only western-market mouses that seems to possibly share this pinout are the original Microsoft "Green Eyed" bus mouse and perhaps a handful of Logitech ones. I am not sure if passive adapters for connecting newer bus mouses to these older cards were ever widespread in the west, since we seem to have moved away from them far sooner than they did in Japan.

Bus Mouse pinouts. the pinouts are:
                    Pin: Description:
                    1: +5v,
                    2: XA,
                    3: XB,
                    4: YA,
                    5: YB,
                    6: Left,
                    7: Not Connected (or Middle),
                    8: Right,
                    9: Ground
The two common PC-9801 mouse pinouts. Seemingly, these are shared with Microsoft bus mouses, although only the oldest of those use the DE9 connector.

It would sort of make sense if the pinout and D-sub connector were chosen to match Microsoft's original mouse pinout, since NEC seemed to cooperate pretty closely with ASCII Corporation (ASCII was basically Microsoft's Japanese arm). I have found evidence that a PC-9801 version of the "green eyed mouse" exists, and that there was a C-bus mouse controller card for it, too.

You could try to rewire an Amiga or Atari ST or AT&T 6300 (Olivetti M24) mouse (or other two-or-more-button quadrature mouse) and have it work. You could also try this guy's "universal bus mouse" idea, and convert probably just about any old PS/2 ball mouse you might own into a bus mouse. Probably some early-ish optical PS/2 or USB ones, too, since some of those just imitated the quadrature signals from their sensor IC's so they could be used with existing PS/2 interface/controller chips as a drop-in upgrade for ball mouse designs.

I opted to buy a mini-DIN mouse, the Logitech PC-93-9MD, from someone in Texas and then ordered a mouse adapter from Japan, since I was in no hurry but my particular PC-98 has a D-sub mouse connector. I also decided I didn't want to wire up my own this time, since making something both small and durable is tough, and the cost of shipping parts from Digikey is almost as bad as just buying a used adapter from halfway across the planet unless you have other things you're buying at the same time.

Does that defeat the point of buying a mouse domestically...?

Well, maybe.

But the price of PC-98 mouse from Japan was nearly as much as the Texas mouse, even without shipping fees. So I think I may have come out ahead just due to how small of an envelope the mouse adapter could fit in. And this mouse had one more button than most of the Japanese ones! - although I'm not sure what all will use it.

I swapped the extremely light weight ball that the mouse came with from Logitech for a much heavier one from a Microsoft two button serial mouse. The mouse worked fine before, but I feel like it's been much more reliable now that I put a heavier ball into it. Maybe it makes it need cleaning less often because the ball is less prone to sticking?

(Picture of a Logitech PC-93-9MD mouse.)
Logitech's PC-93-9MD is a common mouse that can be found domestically in the 'States which will work with the PC-9801/9821 series.

With pin adapters you can also use a PC98 mouse with other computers that use bus style mouse interfaces like Amigas and Ataris. Pretty handy.

Adapting a Newer or Incompatible-Protocol Ball Mouse

You can also take almost any other ball mouse out there and with some major modifications convert it into a bus mouse. Check out "MCbx Old Computer Collection: Universal Mouse" for the basic steps. The real thing to remember is that almost all ball mouses have quadrature signals internally, they just convert them before they leave the casing usually. So if you bypass most of the hardware and add an appropriate amplifier/buffer for the tiny signals, you can make your own bus mouse out of any ball mouse.

Some optical ones also output quadrature signals to stay compatible with older PS/2 mouse interfaces during the transitionary stage between ball mouses and optical ones, so some of those earlier (not 80s early, maybe, but late 90s/early 2000's early) optical mouses can apparently be used, too.



There are a lot of models of PC-98 keyboards out there, but you do need a special PC-98 keyboard or to make an adapter to use a western one. I suggest using an original so all the keys are where they are marked as being.

There are at least two connectors PC-9801 series keyboards used. The original 9801 used a full size DIN connector and is not compatible with later models physically. The pinout of the full-size DIN one is numbered the same as the pinout of the mini-DIN, so I think a passive adapter could make it work.

The earlier boards are mechanical, usually (or maybe always) with linear NEC "oval" switches (the actual product name remains unknown). These are some very pleasant switches, which I compare favorably to vintage linear Alps Electric or Cherry switches, but with key weights similar to those of buckling spring keyboards, almost. Later keyboards use rubber domes; my Epson rubber dome uses Fujitsu's dome-and-slider design like the Sun type 5 keyboard uses. It feels okay, but I prefer the 9801V mechanical board greatly.

There's also a tradeoff here: some things don't work right with mechanical boards. Usually I think this is because they are ignoring BIOS subroutines and directly accessing the keyboard, and not sending the "ready" signal after each keypress that earlier boards are expecting. My SCSI controller's settings are supposed to be accesed via a key combination (ctrl-graph-L), but that shortcut only works when using a rubber dome keyboard due to some oversight by the programmers who wrote the boot ROM on the card. If you want something that works everywhere, and only want one keyboard, therefore, I suggest a rubber dome model... but if you can afford to, I suggest getting one of each. Or just get a mechanical board - stuff that won't work with a mechanical keyboard is still quite rare in my experience. Just be aware if you run into problems that that might be the issue.



There are a couple of kinds of joysticks for PC-98's. There's a Sound Blaster card out there that has what appears to be an IBM-style "Gameport" on-board. I don't know what all uses this, and don't have one of these cards. I've heard it said almost nothing in DOS uses that. It's probably more useful in Windows 9x games, though.

Another kind worth a mention connects via the keyboard port, sharing the bus with your actual keyboard, and can imitate keyboard key presses. These are usually programmable so you can bind keys to buttons for different games. They should be compatible with anything that uses a keyboard for input, even when the joystick port doesn't work. Touhou and Touhou II, for instance, should be playable with one of these. Unfortunately, I have not gotten one yet, and I've heard the one kind I know about has slight input lag.

The third kind, which I think is most common and widely supported, is the Atari-derived digital variant. This is what the PC-9801-86 and PC-9801-26 sound cards use for their joystick ports, and the one(s) on the PC-98 use the MSX style expansion of the basic Atari joystick pseudo-standard - adding a second fire button on pin 7.

A Suncom TAC-2 and two Comrex Commander CR-301's. There are
               two Commanders and one TAC-2 in this photo.
A sampling of my favorite joysticks (which use an Atari-style pinout).
The Suncom TAC-2 is rather famous in some circles; the Comrex Commander seems relatively unknown. I love them both for different reasons.

I stole the coiled cable from a third (sort of unreliable) Comrex Commander for my TAC-2, actually, since I rewired it internally to be able to use both buttons as unique inputs - and the Comrex (unlike the TAC-2) supports the use of its buttons as unique inputs out of the box (and thus it has a cable that can be used to carry the extra signal to the computer/console).

Also note that some joysticks with multiple buttons (at least in the west) would wire multiple fire buttons in parallel to one pin on the cord, meaning that they all act as the same button. Internal rewiring and new cables may be required to fix this on such a joystick. One that does this which is quite popular/famous is the Suncom TAC-2.

Here's an adapter diagram. It took me over an hour to draw to make it look all pretty. Hand drew all of the smaller text in the picture pixel by pixel. :p

Wiring diagram for a joystick adapter.
               From Mouse to Joystick: both sides use male connectors; mouse is either male DE9 or 9 pin male mini-DIN. Joystick is always male DE9.
               Pin 1 to pin 5.
               Pin 1 on the mouse side also is connected to a 2.2 kilo-ohm resistor that connects to pin 8 on the joystick side.
               Pin 2 to pin 1.
               Pin 3 to pin 2.
               Pin 4 to pin 3.
               Pin 5 to pin 4.
               Pin 6 to pin 6.
               Pin 7 to pin 8 (also hooked to the other end of the aforementioned 2.2 kilo-ohm resistor).
               Pin 8 to pin 7.
               Pin 9 to pin 9.
If your system supports it, you can use an MSX compatible joystick by connecting this adapter to the mouse port.
I think all PC-9821's with an 86 sound source built in will work. Don't plug it in backwards!!!!

This adapter will let you use a MSX-compatible joysticks on a PC-98DO or seemingly any model that contains integrated "86 sound." This adapter does not work on the system I ended up getting, which uses "26 sound". I think the only solution on computers in my situation is to get a dedicated "86 sound" compatible card - probably a PC-9801-86. You could maybe also get one of a handful of clones that never seem to show up for sale but purportedly exist. I looked for those first in the hopes that they would be cheaper - no cigar. But maybe you will have better luck!

A PC-9801-26K or similar older card with a 2203 that featured joystick ports would also work, but would be the same sound hardware you already had on your board anyway.

Picking a Joystick/Gamepad

Generally, with joysticks, there are a few things to keep in mind when buying. These have to do with the things that you think of when you imagine your ideal joystick.

My Recommended Joysticks/Gamepads

I can't help with all of these criteria, but what I can do is tell you what I personally value in a joystick, and maybe show you my favorites.

Want a joystick or controller, but aren't sure which ones are good, and don't know where to even begin with that list? - I'm no expert, but I at least can give you a few very good options. I firmly believe the sticks I discuss here to be good (at least when in good condition); I mainly claim not to be an expert because there are many joysticks I likely have never seen or heard of which might actually be quite good as well. Ultimately, it's subjective, and it's up to you to decide what you like in a joystick or gamepad.



Your PC monitor may or may not work with the PC-98, as I have already alluded to. Its VGA connector almost certainly will not fit into the output on the PC-98, even if it is electrically compatible. Here is a drawing I made that corresponds to the adapters that I wired for myself and my friend.

(Picture of a Logitech PC-93-9MD mouse.)
This is drawn as if the two connectors' solder sides are facing each other, wide side up. The physical wiring will look pretty similar in this situation.

I am not 100% sure the ground wiring is all correct, so if you get noise definitely look first at pins 12 and 8 on the DA15 side and pins 5 and 10 on the VGA side. Perhaps I need to separate them from each other?

According to the VGA pinout on Wikipedia, pin 5 on the VGA connector is supposed to be the ground specifically for the HSync signal, and pin 10 for the VSync signal. So if you can figure out which is which on the DA15 (PC-98) side (if any), then perhaps that will reduce noise.

It looks fine on my CRT, though, which is why I have not bothered to mess with it much. I followed the DA15 pinout from here.

Of course, there's also a solid chance your monitor will not be able to sync to the PC-98's 24KHz mode. If yours is like this, but you happen to have one that can sync to 15KHz (like my Commodore 1942 CRT or my Dell U2410 LCD), you can see if there's a DIP switch to make it output at 15KHz. On my Epson, this switch exists on the front panel and is labelled "HS24K."

When I first got this Epson, I had not yet bought a CRT and was hoping my LCD would do the job. Since 24KHz is in between 15KHz and 31KHz, I was a little hopeful, and I wired up my adapter while I waited for it to arrive.

When it got here, I got nothing. But I was able to confirm operation by switching that DIP switch on the front panel, which made it show up on the Dell. I don't recommend just leaving it there, because a lot of stuff will break or work weirdly. It's not really a tenable long-term solution. Also, it introduces "scaling artifacts" such as uneven pixel widths, and most stuff that uses the higher color modes will be cut off halfway down the screen.

Anyway, that happened, so I needed to get a CRT or a scaler (or another LCD). I ended up going for a CRT.

Unfortunately, not all PC-98 monitors can sync at 24KHz either. Some of the later Windows 9821 monitors will not and run at 480p minimum (around 31Khz).

Many if not all Sharp X68000 screens will also do 24KHz and can be used, by the way. The X68000 appears to use a compatible connector, too. Not sure about FM Towns, though. That's something that might be worth researching.

Make sure the monitor you are looking for has analogue RGB, not just digital. Many older monitors have only digital RGB, which will limit the number of colors and types of software you can use.

Additionally, finding a nicely priced one will be challenging, and you probably will get murdered on shipping. I won mine in an auction for $30 and paid nearly ten times that much in shipping, which was an unexpected surprise to say the least. I'd thought it'd be maybe $150 or so to ship. Apparently, Buyee re-packs stuff after inspection if you choose to have them inspect it, so I am nearly certain that Buyee's packaging is the reason it cost so much. For that reason, I am considering Buyee alternatives in the future, but we'll see. It did at least arrive very well protected and intact. But for a monitor that I bought 'untested' looking absolutely filthy, I don't know if I would have spent that much more in shipping had I been given a choice to not repack it.

Unfortunately, my friend had already snagged what seems to have been the only really nice monitor at a fair price on the site, so I was left to deal with either super overpriced stuff or stuff that wasn't guaranteed to actually work, or overpriced stuff that I would definitely have to repair.

(Four pictures of the dirty PC-KD851 monitor that I bought on Yahoo Auctions Japan.)
The original pictures from the Yahoo Auctions Japan listing for my monitor. These are what I had to go by when choosing to bid on it.

I ended up deciding this filthy thing, an NEC PC-KD851 monitor, was my best bet for getting something that worked, since the seller said the screen would go bright when turned on or off. I operated under the principle that filthy untested stuff is more likely to be fine than spotless stuff that's tested and that the seller thinks is broken.

To be honest, most stuff I pick up tends to be fine, and it probably wouldn't have been kept around long enough to get so filthy if it hadn't worked back in the day when it was presumably stored away.

The thing came, and it took hours of scrubbing at it with a damp or alcohol-soaked rag to get most of the grime off. But it cleaned up pretty nicely!

(Before and after cleaning the monitor. Pretty much all the dirt came out.)
Before and after cleaning the monitor. Pretty much all the dirt came out, but I was sore from scrubbing afterwards. Took maybe two or three hours.
The dirt's a lot more noticeable at higher resolution (click the image).

The PC-KD851 was originally made for the PC-8801 series, it seems, rather than the 9801. Specifically, I've found a catalog scan that says it works with the PC-8801mkIISR, which indicates it's from around 1985. But since it has an analogue RGB input, and since the 8801 also could output at 24KHz, I decided it had a good chance of being compatible. I think the seller also listed it as being PC-9801 compatible, actually.

The PC-KD861 appears to simply be a better version of the 851 that can also do 15 KHz. So I'd say that'd be one worth keeping an eye out for.

Once again, this needed to be plugged into a stepdown transformer before I felt comfortable turning it on. Thankfully there's an outlet on the back of the Epson that I can use to daisy-chain it.


OSSC - Open Source Scan Converter

Another approach is to use an existing western monitor that can't do 24KHz natively by using an external digital video scaler that can handle it. I used an OSSC version 1.6, which is now an older version of OSSC but which seems to work fine. Tested on my Dell U2410 monitor. If it will support 56.4 Hz video or so, it should be fine.

You will need to find a remote for your OSSC if you get one - most functions and configuration cannot be done with the on-board buttons. it's good to note that it doesn't need to be the remote that was originally shipped with it. If you hold down the rightmost button (closest to the LCD) on the front of the scaler unit while switching it on, you can program it to use the codes from some other remote control that outputs "NEC Protocol" infrared codes. Examples of some remotes I have that work with it include my Pioneer A/V receiver and laserdisc player remote controls, as well as my ancient Sony universal remote. You could probably even use a Game Boy Color or an HP-28C/28S/48S/48SX/48G/48GX calculator with the appropriate software, since both of those have infrared LED's that are software controllable! - I don't actually know what the range of the HP-48 series transmitter LED is, though.

OSSC's ship with remotes, so if you buy one new this is not an issue. You can buy the remote in question from third party sellers, but don't bother getting one pre-programmed for the OSSC specifically unless the price is really good. If you want to get one that is dedicated for the OSSC and has enough buttons to send all the controls it can use, then you can get an "L336" learning remote control and send it codes from some other programmable remote control that is set up for a device you don't have. Maybe using multiple device settings if you run out of buttons on the first one.

To program the L336, you should first hold the button for the 'output' you want to program a key on - so the 'TV' button for instance. When the light comes on on the remote, aim your other remote control at the L336 and press the button code you want the L336 to be able to send. Repeat as necessary for all buttons you need. I also suggest that you get or print a label/overlay for the L336 to remind you which buttons do what. It really is helpful if you are trying to fine-tune something. You will probably need to do a little fine-tuning to make a PC-98 look just right on your LCD.

I vastly prefer the look of the video output on my CRT; it just feels better to me. But the costs involved can be vicious, and a CRT monitor unfortunately takes up a solid chunk of space… even for a small screen. The picture quality from my OSSC is good; any screenshot you see in my post here is originally fed through my VGA splitter, then OSSC, and eventually into my HDMI capture USB.

The optimal settings I have found for my OSSC so far, for the output from my 486GR, were discovered by running "MPS" (Multi Paint System or Maguro Paint System/Tuna Paint) and drawing a red line around the permimeter of the screen to determine horizontal and vertical back porch & front porch settings.

Screenshot of MPS on PC98 with a red box around outside of
                    screen and the Open Source Scan Converter advanced sampling
                    settings menu opened. Values are:
                    H. samplerate: 848
                    H. s.rate frac: .00
                    H. synclen: 64
                    H. backporch: 85
                    H. active: 640
                    V. synclen: 3
                    V. backporch: 31
                    V. active: 400
                    Sampling phase: 135 degrees
Sampling settings to get a nice centered crisp picture on my PC-486GR with an OSSC.
These settings might vary wildly for your system, but give these a shot!

Then I filled the whole screen with black and adjusted the black levels (red, green, and blue offsets, or "brightness"). I did this until a colour picker on my computer that was showing a picture from HDMI capture of the OSSC was showing numerically close RGB values for <1,0,0>, <0,1,0<, and <0,0,1>. Since RGB values are between zero and 15 on the PC-98, a 24-bit PC RGB value would be <16,0,0>, <0,16,0>, and <0,0,16> respectively. But I just got somewhere close to that and said, "that's good."

For "white levels" (red, green, and blue gain, or "contrast"), I brought the gain controls down until RGB <15,15,15> was just barely reaching or very close to reaching PC RGB <255,255,255> - so that bringing any given one of the sub-colors down by one on the PC-98 would drop the brightness proportionately on PC RGB. This is to avoid "overexposing," or clipping the highlights.

Screenshot of MPS on PC98 with a solid near-black
                    (RGB 1,0,0) screen and the Open Source Scan Converter
                    'Video In Proc' settings menu opened. Values are:
                    Video LPF: Auto
                    YPbPr in ColSpa: Rec. 601
                    R/PR offset: 146
                    G/Y offset: 148
                    B/Pb offset: 147
                    R/Pr gain: 17
                    G/Y gain: 9
                    B/Pb gain: 10
                    Pre-ADC Gain: 5
                    Clamp/ALC offset: 0
                    ALC V filter: 512 lines
                    ALC H filter: 16 pixels
Even just visually seeing if bumping values up changes the picture is useful,
if you don't have a capture USB and are just trying to make the picture nice on your monitor.

By the way, to adjust the palette in MPS, you left click on the numbers under the R, G, and B rows in the palette to raise them by one, or right click to lower them by one.

I also adjusted the Pre-ADC gain down for a coarser adjustment before fine-tuning.

O.S.S.C. screenshot with a DOS prompt in the background. the
                    O.S.S.C. display shows me about to save profile zero after
                    making these adjustments.
Don't forget to save a preset when done!
Maybe also associate the RGBHV input with your preset, so you don't have to manually load it after switching the OSSC on.

You may want to not only save a profile, but also export your settings to a micro SD card after doing this. Note that settings often don't survive firmware updates and backups from older OSSC firmwares might not be able to be restored, so keeping notes might be important, too.


Getting a Hard Drive

If your PC-98 or compatible doesn't come with a hard drive, then you might need a SCSI controller.

You might also need a parallel SCSI drive; these are getting tougher to find at good prices. A good long term solution might be to get something like a SCSI2SD, BlueSCSI, or ZuluSCSI board that can emulate one or multiple SCSI hard drives.

I happen to have a 4GB Seagate Barracuda from 1996 that still works, but I also took this opportunity to get a ZuluSCSI board. I don't know how durable the SD cards will be, but they're a bit easier to get replacements for than nearly 30 year old HDD platters or bearings or spindle motors for sure.

I stuck my ZuluSCSI board in an old external HDD enclosure to make it feel more period correct, even if it's much, much quieter. I think I'll use my Seagate as well, but I'm just not sure how often.


Getting an Optical Drive

If you want to transfer files via CD, or play or install something distributed on CD, you may need to get a drive if your PC-98 doesn't have one. Much like hard drives, your main options (depending on your model of computer) are IDE drives and SCSI drives, as far as CD's are concerned. PC-9821's often (perhaps always ) came with IDE controllers; 9801's and Epsons didn't (although I think some of the last Epson 98's did; seemingly the models introduced in or after September 1993 have an IDE interface built in, so the PC-486H* and PC-486F* models; 486G* and 486S* models and earlier do not).


IDE Drives

Some later PC-98 models came with built-in IDE CD-ROM drives. If yours doesn't have one, but is late enough to be using IDE instead of SCSI, then there's a decent chance one might be able to be installed in an open bay, I'd think. In the Ce2 and Cs2, it looks like the model is NEC CDR-260. They seem to have sold these drives in the 'States, so maybe you can remove the front bezel from one of the US-market ones and stick it in a '98 and have it work. Perhaps it was sold in other countries as well.

If your PC-98's built-in optical drive isn't working, it may be broken. My friend got two systems, and one would not respond to the eject button or turn its LED on at all. The other one, from the unit in otherwise worse condition, would blink, and after she swapped the drive into her other unit it worked just fine.

You might not be able to pick any old CD drive; they may look like "normal" IDE drives, but in the Ce2 and Cs2 at least, they might actually use some non-ATAPI command set. We (my friend and I) aren't quite sure yet. I've seen one person suggest that the CDR-260 might be one of the earliest ATAPI compatible drives, but I can't guarantee anything. If it is truly an ATAPI drive, then I expect you could put in some other standard IDE CD drive and have it function, although you still might not be able to get one where the tray, LED, and eject button line up with the holes in the case. I'd be interested to know if anyone manages to finagle something into working!


SCSI Drives

The other option is a SCSI optical drive. Since my PC-486GR never came with an optical drive internally, and doesn't even have IDE, this is my only option. Working SCSI CD drives can be had for prices that aren't ludicrous still, but expect to pay about what you would for a used Blu-Ray writer drive for one (as of 2023).

ZuluSCSI can also emulate a CD drive, if you are so inclined. As of now it looks like the boards currently on the market can't do CD Digital Audio (CDDA) playback, which would be a huge minus for me. maybe there'll be a hardware mod or something that I can do to retrofit it to mine, since there is now a hardware design (which has not been produced to my knowledge) that also carries CDDA.

I don't know which if any PC-98 models used internal SCSI optical drives, but I don't have that option so I would be daisy chaining my CD drive to my SCSI bus after (or before) the hard drive. Make sure your hard drive (if applicable) and optical drive SCSI ID's don't overlap; you may have to adjust some jumpers or DIP switches or press a button on the casing of your drive to change this and avoid overlap.

Then, with SCSI optical drives, the problem becomes making it work with DOS.


DOS CD Drive Configuration

DOS doesn't know what a CD drive is, normally. It needs extensions loaded into it to be able to access them. This is also true in the IBM-compatible DOS world, but the drivers are a little different, seemingly. This section will basically assume you're using a SCSI drive, but might mention alternatives for IDE drive users here and there.


NEC Brand Drives
If you are using an NEC brand SCSI optical drive and an NEC SCSI-1 controller, you can probably use the NECCDA.SYS driver. If it's an NEC SCSI optical drive and an NEC SCSI-II controller, I think that means you need the NECCDB.SYS driver instead. There's also NECCD.SYS to try, as well as every other letter in the range of NECCD[A-K].SYS at least.

Yeah, I know it's annoying. I can't find nice documentation to figure out which drives go with which drivers, but I know at least some of the drivers are for IDE drives. I suspect most if not all of the NECCD[C-K] range are for various IDE variants.

Not all of those drivers come with NEC MS-DOS, even in version 6.2 (the last released version). In addition, the above only seems to matter if you are using an NEC branded SCSI drive; I wasn't able to get that driver to detect my drive (non-NEC) at all unless I spoofed an NEC vendor ID, and if I did that then the computer hung during initialization of the driver. But by most accounts, if you are within the NEC ecosystem, the above are the drivers to use. It may be possible that some other drives will also work with some of those drivers. I can't confirm this.


Other (Non-NEC SCSI) Drives
If you aren't using an NEC brand drive/controller, it could be that trying to use the NEC drivers makes your system freeze.

Mine did freeze; I suppose it could just be that the NEC driver is doing an "Epson Check" and intentionally sabotaging me for not using their hardware. If that is all it is, then there's supposed to be an Epson installer tool somewhere specifically made to patch out these "Epson Checks" in NEC software. But I didn't think of that until afterwards, so I looked for other, non-NEC solutions.

I had to use a different driver to connect my SCSI CD drive, which I found on and in case anything ever happens to it. The driver in question is CDSD.SYS, which is under an open source license, from what I can tell. The source code seems to be available here - note that it also appears it can be built for FM Towns! There is also a version of the source code, which looks like it may be older, on, which I have also used to find a floppy disk image converter in the past.

The "newer" version might actually be patched for FM Towns, so if there are issues maybe try the older version.

The FM Towns developer that is hosting that first CDSD source download also has an English-language writeup of the problems that he/she/they had, and patches for them. This writeup can be found here.

There's additional notes about patches for CD-SD here, seemingly from the author of the T98-Next emulator author, to make it work with CD Digital Audio properly. I haven't been able to test if the version in the download I am hosting is CDDA patched yet.

I have successfully used the last of those options (reading the 'additional notes' I mentioned above and following the directions there exactly, using the downloads from and archived versions of the links for Microsoft assembler tools that used to be hosted on the M$ website) to make a version of CDSD.SYS. I just have to try it out when I get back home with the physical SCSI CD drive I got for Christmas. I will host that file as well, if it ends up working.

Finally, I should note that this Japanese blogger seems to have figured out how to assemble and link the program without using any Microsoft software, via the assembler JWASM, the linker VAL, and EXE2COM to replace Microsoft's own EXE2BIN. Might be worth checking out how they did that. I haven't tried it yet.

Of course, hopefully you won't need any of that, and the driver (or one of the others) in this zip file will do the job for you!!

Download: PC-9800 Series CD-ROM Driver Collection (v1.1) [FD].zip – 137 KiB


Automatically Adding a Drive
If doing a fresh install, or maybe also if running NEC DOS, you can try to let the installer automatically configure your driver for you. It might work, even if your drive is not NEC. I can't guarantee anything.

If it hangs after a reboot, though, you will need to use a DOS boot floppy disk to edit the hard drive's AUTOEXEC.BAT and CONFIG.SYS files to remove the offending lines (which will contain the phrase CD_101 in every case I have seen so far). You can also just prefix those lines with REM (the space after REM is important), which is how you comment out lines in both BAT files and in CONFIG.SYS.

NOTE: MS-DOS versions prior to 6.0 DO NOT support 'REM' in 'CONFIG.SYS'! But they should still support it in AUTOEXEC.BAT.

If DOS is already installed and you want to add a drive, I think the correct step is probably to run the CUSTOM command, which seems to be NEC's tool for automatically managing CONFIG.SYS and AUTOEXEC.BAT for some typical use cases. I can't really help you with it, though, because I don't even know where to begin and I am more comfortable manually editing CONFIG.SYS and AUTOEXEC.BAT anyway as far as CD drives are concerned.


Manually Adding a Drive
If you've never messed around much in DOS before (including western versions), some of this might be new to you. It's not too new to me, but that doesn't mean I love the process, either. Basically, though, here's the steps as I understand them. I hope I don't leave anything out.

Step 1:
Step one is getting the driver files. Some of them (NECCDA.SYS, NECCDB.SYS, NECCDC.SYS, NECCDD.SYS, and maybe(?) NECCDCHK.SYS) are included on the NEC MS-DOS 6.2 floppy disk set (on disk 1). They should be installed already, but if not, you can copy them off of the floppy disk. They will be named with .SY_ extensions instead of .SYS, because these are compressed files that need to be unpacked. If they were installed already, they are already unpacked.

To unpack a file like this, you need EXPAND.EXE, which is available in uncompressed form on NEC MS-DOS 6.2's disk 1 as well. If you booted from your hard drive and put the DOS installer disk in the first floppy drive afterwards, then your hard drive will be A: and your floppy disk will be in drive B: - this is different from the IBM PC, but important to note.

Assuming that the above is true (you booted from your hard drive), the following should work to change your 'current directory' to the root of the B drive and unpack the file back to the hard disk.

cd ¥

If you don't have the A:¥DOS directory, then you can just output it to A:¥NECCDA.SYS instead.

Also note, of course, that in Japanese DOS/Windows, the yen sign (¥) serves the same function as backslash (\), and is actually using the exact same character numeric representation internally. It's just that Japan's "code page" replaces \ with ¥.

Step 2:
Step two is editing CONFIG.SYS.This is a special file in DOS that tells it about the drivers it should load at startup, and how it should load them. In other words, because we need to tell DOS about our CD driver, it must have a CONFIG.SYS entry.

(Screenshot of me editing my config.sys file.)
Me editing my CONFIG.SYS file. I use 'jed' as my text editor, but 'SEDIT' is the one that is shipped with NEC DOS 6.2.

Unfortunately, as far as I can recall, you can't load a CD driver without first loading some other drivers. I've provided my CONFIG.SYS file, in case it helps you to figure things out. A lot of it is irrelevant, but I think it depends on at least HIMEM.SYS and EMM386.EXE to work properly. You will have to adjust it to look in the right places, if your hard drive is organized differently from mine. I think mine is pretty standard in this instance, though.

So here is my CONFIG.SYS:

NOTE: If you are directly copying and pasting this text into a file and moving it to your PC-98, you MUST replace all ' ¥' characters with ' \' characters before moving it to the PC-98!
This is because a unicode '¥' character is represented by different bytes than a JIS-X-0201/code page 932 '¥'. The byte representing the character '\' in ASCII is the same byte that represents '¥' in CP932.






I believe the important bits there are the lines with HIMEM.SYS, EMM386.EXE, and CDSD.SYS. If they aren't already there, anything else in this example can probably be omitted. For instance, the LOGITEC things are for my specific SCSI controller, but I don't think you need to have a special driver loaded for your particular controller board. Just try them if you have problems (with your appropriate card's drivers, of course).

The /P=64 argument to EMM386 can likely be omitted; EMM386 defaults to using all of the expanded memory area it can (rather than just 64 pages, like that is specifying). It was just automatically added by something or another and I haven't had a reason to change it yet. But the important arguments are the ones to CDSD.SYS - particularly, you need to know your optical drive's SCSI ID and feed it as an argument to CDSD or it will fail with a complaint about an invalid SCSI ID. It seems to be a somewhat common convention to make the drives with ID's 5 and 6 optical drives, so if you only have one or two optical drives /I:5 makes sense. To add a drive 6, you'd simply add a second CDSD.SYS line... I think. If my understanding is correct, in that case you'd also need to name the driver (/D:) something else for a secondary optical drive; maybe CD_102. The name actually apparently does not matter, as long as it matches up with a line in AUTOEXEC.BAT (which we will get to next).

Step 3:
Finally, we need to edit AUTOEXEC.BAT. This is another special file that DOS looks for and reads at startup. The difference is that AUTOEXEC.BAT runs commands just like a user can at a command prompt manually; I don't think there's a way to manually load in drivers like CONFIG.SYS does.

In our case, AUTOEXEC.BAT needs to run a program called MSCDEX.EXE, Microsoft's CD Extensions program. I suppose it's what DOS calls a TSR program (terminate-stay-resident), in that it loads its code into memory for other programs to hook into later when they need to access the CD drive. It's a sort of workaround for the lack of multitasking to make it so programmers don't have to have their own CD driver as part of their software's code. I guess you could also say it's like some horrible kind of shared library (like DLL's).

Anyway - here's my AUTOEXEC.BAT.


You can ignore the SMARTDRV line; it's for hard drive data caching, which speeds up disk drive use sometimes. I don't know if it does anything for CD speeds. MSCDEX is the only critical one, I believe.

It seems to be another convention with the PC-98 for things to map the optical drive to drive letter Q. Weird, isn't it. I think I might get it though; if they are the farthest drive letters down the list that they can be, then adding another hard drive or floppy drive is less likely to mess up any scripts that might have been written assuming that drive 'D:' would be a floppy disk or something. Since the PC-98 uses a proper Shugart interface instead of IBM's version of it, it can have four floppy drives, so this makes a little more sense. But if you want to change the drive letter from 'Q:' to something else, you change the /L:Q to /L:(your-drive-letter).

Two SCSI Drives
Here's how I would guess you would change it to use two CD drives with SCSI ID's 5 and 6, mapped to drive letters P and Q. This is only a guess.

Partial CONFIG.SYS file:


Partial AUTOEXEC.BAT file:


One IDE Drive and One SCSI Drive
You should also be able to mix and match drivers. I am assuming a driver file for the IDE drive is NECCDM.SYS, but you may need a different file. If you have an internal IDE drive and an external SCSI drive, you might try something like this:

Partial CONFIG.SYS file:

REM NEC internal IDE CD drive doesn't have a SCSI ID
REM External SCSI CD drive is SCSI ID 5

Partial AUTOEXEC.BAT file:

REM NEC internal IDE CD drive
REM External SCSI CD drive

One final reminder: I do not know for sure that all of this works like I think it does. But that experience which I have with DOS leads me to believe it is so. DOS just has a way of defying my expectations.


Floppy Drives: to Use or Replace?

Planning on using real floppy disks? You'll need some good diskettes. These are no longer being made, so you'll have to buy new old stock (or used, if you feel very lucky) - unless you already have some of course.

Older PC-98's use DD (double density) diskettes and drives, and the drives can't reliably write to 1.44MB HD floppy disks which have lower coercivity, and need stronger magnetism to flip a bit from a zero to a one or vice versa. So if yours is an older model (before around 1993 or 1994), you almost certainly need DD diskettes.

It may also be a good idea to invest in a cleaning kit, or perhaps find a way to clean the drives without one. It only takes one bad disk to mess up a floppy drive and make it need a cleaning to avoid ruining good disks.

I wish it were easier to keep using real ones, because I do happen to like using them... when they work.


Writing Floppy Disks (Linux)

The key to writing floppies for a PC-98 in Linux is to use a program called "ufiformat." Especially if your PC-98 is not new enough to support 300 RPM 1.44MB disk reading/writing, it is absolutely essential.

I wrote a script for me and my friend that handles the details of setting up a floppy disk for the PC-98 series. It depends on the following utilities (and perhaps more).

The sudo calls can all be removed if you plan to invoke the script as root. So I don't actually consider sudo to be a hard dependency.

It currently is only written to work for 1.2MB floppies, which in my experience constitutes a huge portion of the disks that you will use.

#! /usr/bin/env sh
# Reformats a 3.5" floppy for PC-98 360RPM and then writes a disk image.
# Use with a USB floppy drive
# define help text function
helptext() {
  echo "Usage:"
  echo "$0"' [-s] image-filename'
  echo "  -s: skip ufiformat (skip changing disk type to 1.2MB). Optional."

SGDEV="$(lsscsi -g | grep 'USB-FDU' | awk '{ print $7 }')"

# make sure a file was given
if [ "$#" -gt 1 ] && [ "$1" = '-s' ]; then
# skip ufiformat, and then move past the '-s' so that "$1" now contains
# our image file name
shift 1
sudo ufiformat "$SGDEV" -f 1232

echo 'waiting 5 seconds'
sleep 5

SDDEV="$(lsscsi -g | grep 'USB-FDU' | awk '{ print $6 }')"

if [ -e "$1" ]; then
# use cat
echo 'Writing file to disk.'
sudo sh -c 'cat "'"$1"'" > '"$SDDEV"
echo 'Nearly done now...'
# 1>&2 sends the output of the command (echo in this case) to "standard,
# error," which is a distinct output stream from "standard output" that
# will show up even when a program's output is being 'redirected' or 'piped.'
# It's good for error messages.
1>&2 echo "Error: The chosen image file to write to disk does not exist."


I have yet to successfully write Ys, which should be a smaller game that uses a DD floppy instead of HD… but for whatever reason, the game I write always has some bugs that don't appear in emulators. I almost wonder if it is intentional copy protection, because my friend was also able to get the same bugs to appear on a real diskette as I had with my Goteks.

If you have an original physical copy, you could probably make a kyroflux or greaseweasel disk dump which would work... but mine is from a Japanese online game market which bundles emulators with games - I extracted the disk image from it. So perhaps I need to try to find an original physical copy.


Writing Floppy Disks (OpenBSD)

OpenBSD is my darling OS. It does not have ufiformat, though. I can't use OpenBSD as much as I'd like to, but it looks like it might be possible to create a PC-98 compatible (1232 KiB) floppy by initializing it with makefs. This has not been tested as of yet!

$ makefs -o floppy=1232 -t msdos


Writing Floppy Disks (Windows)

I have absolutely no clue how to format a floppy disk to 1.2MB at 360RPM under any version of Windows. My one floppy disk imaging tool of choice doesn't work, because it assumes all floppies are 1.44MB. And I don't even know what the API call would be in software to communicate a mode change to the floppy drive in Windows. I guess Greaseweazle would work, since it lets you read and write to the disk with no interference from a floppy controller. But that's a hardware solution no other platform needs.

I tried to help my friend to do it in Windows and came back empty every time we tried. Thankfully she also has a laptop with Debian on it, so we were able to write disks in a matter of minutes that way.

This message is brought to you by the Society Perpetually Against Microsoft.

(Update/for future expansion: I perhaps have found a way while looking for tools to dump ROM's from PC-98 C-Bus cards.)



Planning on forgoing floppy drives? You'll need to get some floppy drive emulators. A lot of games require that you have disks in two drives at once, so just one probably won't work, until/unless the FlashFloppy firmware fork for emulating two drives with one Gotek comes together.

The Gotek drives and FlashFloppy firmware (you can't use the stock Gotek firmware) have been discussed at length elsewhere on the web, so I will probably talk about what I had to do for my Epson but won't give general advice on how to get FlashFloppy onto a Gotek just now.

Where to put the drive emulators?

You want to just replace the original drives? Well, depending on your exact model, that might not be too easy. A lot of machines, both from Epson and from NEC itself, have floppy disk shaped slots moulded into the outer casing for a pre-set number of drives, and won't even accept other real floppy drives, if they have the eject button in a slightly different position. I consider this to be kind of a jerk way to do things, but it seems that it was quite common for companies to do this to make their drives integrate more smoothly/aesthetically into the casing.

If your PC doesn't have nice open rectangular holes in the case, then even if you don't want to modify your casing, all hope might not be lost. Note that I have not done this yet - but many if not all PC-98's have an external floppy drive connector on the back of the system. It uses a variant of the so-called "centronics" connector. I believe it should be possible to modify your system to identify external drives as the first and second drive and to prefer those over the internal ones.

Again, I haven't done this, but if the floppy drive 0 and 1 selection pins are exposed on the "centronics" connector, then you could simply disconnect the internal ones or flip some BIOS setting/DIP switch and be good to go. If those lines aren't exposed externally, you can simply hijack those lines from the internal floppy drives' ribbon cable and pass them out with a method of your choosing.

I might elaborate on this if I need to, but for now I will assume you can figure out a floppy drive solution that works for you, and I will explain how I did mine (internally).

Adding Goteks internally on the Epson PC-486GR

I decided I was going to forego floppies. I just can't trust them anymore and I know I'm going to run out of good ones some day. Additionally, it could be that I just had the DIP switches configured wrong at the time and the floppy drives actually are just fine, but when I first got it, it wouldn't boot anything. I haven't tried the real drives since fixing the DIP switches. I think the last owner had them set up for external floppy drive booting.

The Epson PC-486GR has two or three floppy drives internally, depending on your configuration from the factory. These drives are a little... quirky. But they do work and can be adapted to use Goteks instead.

For starters, the Epson's 3.5" bays have brackets to fit them in a 5.25" wide slot in the case, but these slots are not as tall as a standard 5.25" bay slot, so you can't just use a normal PC mounting bracket for attaching a floppy drive. I was unfortunate enough to have pre-emptively ordered two adapter brackets that I now cannot use. Anyone want them?…

The good news is that the brackets that come in the Epson are able to mount a standard 3.5" floppy drive or Gotek just fine - with the caveat that you won't have a nice plastic bezel to cover up the gaps on the sides of the Gotek. That's why I have masking tape on the front of mine. When I'm not looking directly at it, it's fine! And it blocks a little of the noise from the blower fan on the 75 MHz 486 DX4 that mine has been upgraded with by the previous owner inside.

Yes; I know the sticker says 50MHz DX2. But there's some other kind of accelerator card - which the Japanese seem to call a Geta - inside of it that I am pretty sure is not an Epson product.

I am guessing they are called "geta" because of the way that the CPU sort of sits on a PCB with pins (like the vertical boards on the shoes) underneath that sort of look like stilts. This board is required because the 486 DX4 runs at 3.3 volts rather than the 5 volts of the original 486 SX/DX and DX2, thus needing a voltage converter between it and the PC itself.

…But I digress.

The bad news is that if you bought one of these with the 2x 5.25" drive configuration, you weren't given that bracket! - You might have to either find someone selling the 3.5" floppy drives for one on their own or else make your own adapter (or find a pre-made one that fits the slot). If you have access to wood and are a little crafty, you could probably carve one. Or you could 3D print one. Maybe you could also make one with Lego, or something? - I believe, but cannot confirm, that the 486GR's floppy drive bay is the same as the one in some of the earlier Epson PC-286 and PC-386 lines, so you may be able to find a listing for drives from one of those. That is, if they were offered with 3.5" disk drives. NEC was kind of late to move to 3.5" disks.

The 3.5" drives used in the 486GR2, 486GR2E, and 486GR3 models– the versions of the 486GR that aren't 5.25" only– are model MD3541G, which seems to have been made by Canon (yes; that's Canon, the camera and printer company. Not by some other company called Canon that you never heard of).

By the way, it seems to be confirmed by that last link that Epson's PC-386GE (PC-386GE2, PC-386GE2B, PC-386GE3) and PC-386GS (PC-386GS2, PC-386GS2E, PC-386GS3) also use the MD3541G. So, if you find one cheap, maybe you could consider using it as an oversized external 3.5" floppy drive unit for your 486? :)

An additional oddity is that the Epson uses laptop-style 26 pin floppy disk drives that connect via flat flex cable, attached to an adapter board that converts them to use full-sized 5.25" drive card edge connectors and large 4-pin "molex" power connectors.

Picture of the original floppy drive ribbon cable and
                    adapter board.
The transistor and resistor on the adapter board appear to act as a NOT gate to invert the 'density' signal, which is inverted on the drive or computer itself for some reason.

Since I don't want or need that adapter board anymore, I need to find another way to deliver power to the Gotek and to make the ribbon cable actually reach the drives' connectors, since the Goteks don't reach the backs of the drive brackets. This means "Molex" to "Berg" power adapters, as well as IDC to card edge floppy adapters, plus some homemade extension boards to bridge the remaining distance from the IDC connector to where the ribbon cable connects at the rears of the brackets.

My Gotek floppy drive solution, with extension board,
                    converter board, and power adapter all connected. The
                    extension board is sort of hideous looking, but it does the
Isn't it beautiful?

Someone might be quick to criticize my soldering work. I honestly think it's fine. And it took less time than waiting for a custom board to get printed somewhere, or for me to learn to etch my own boards.

Do note, however, that in the final installation there is more clearance between the metal shielding and the extension board than there may appear to be in this photo. Additionally, the insulated wires jumping over the board keep the board act as a "bumper" that prevents the perfboard from contacting the metal above it.

It's been bulletproof since installation, honestly. I probably wouldn't make the extension boards exactly like that again, but I don't regret doing it this way this time.

Photo of the whole thing, with both Gotek drives
                    installed, with all four adapter boards and two power
                    adapters hooked up.
The final product.
Without the extension boards, the cable would not reach both drives.

I have noticed that whenever the drives are not active, the drive select lines seem to cycle with a square wave, which causes the LED's to flicker fast enough to appear constantly dimly on. I have not figured out why that is, nor how the original drives sidestepped the problem - although I assume that saturating a capacitor was involved. The drive lights come on to full brightness normally when the system actually tries to read something or write something.

Just because I feel like trying to be helpful, I'll share an adapter board that I designed afterwards which I think will work fine. I don't recommend making the spacers by hand like I did; it took a lot of time and I probably inhaled a lot of leaded solder fumes. It also required two extra connectors. I have never had any of my board designs actually get printed, however, so I apologise in advance if there are any issues. Please get in touch.

(Picture of an extended floppy adapter board drawing from
                    kicad. has solder points on one side for an IDC connector,
                    and an edge connector on the other for a 5.25 inch drive.
An adapter board for my Epson (and other 3.5" floppy drives/Goteks in 5.25" bays) that I made in Kicad but never tried to print. Who knows? Maybe it works just fine.

The board is about 5.5 centimeters long, and will be a little longer with the right angle female IDC connector soldered on (estimate: ≤6 cm). I think it should work; give it a shot. Get it with hardened gold contacts on the edge connector if you can. Better to make or buy one board than to both make one and buy another. And even if it doesn't work, you can probably cajole it into working with a knife and an iron.

Download: – 955 KiB


Touhou Project Notes

The Touhou games are a huge reason a lot of people might buy a PC-98, and I have grown to enjoy them, so maybe they're worth mentioning in a special section.

If you buy a "CanBe" or "Cereb" series PC-98 (Pentium era, uses a sound chip equivalent to a PC-9801-118 card), they use a YMF297 FM chip instead of a YM2608, and this presents some compatibility issues with the sound drivers used by the Touhou games (and other DOS games). But if all you care about is Touhou, I'm happy to tell you that these issues are fixable! So don't feel like those cheap Pentium-class CanBe's you see are utterly worthless! I'd not recommend one if you want to play a LOT of DOS games, but for Touhou it's plenty.

Touhou 1 (Highly Responsive to Prayers) with CanBe / Cereb / PC-9801-118 Sound Sources

The first Touhou game uses a very different driver than all later Touhou PC-98 games. There are notes in Japanese on this page that describe how to make Touhou 1 run by downgrading a driver.

"Railway Goes On Far Away" is a free game that contains a working version of the MDRV98.COM file you need to run the first Touhou game on a CanBe. Simply take MDRV98.COM and replace the file in your Touhou 1 installation directory (I would make a backup of its MDRV98.COM as well, first). This downgrades the driver from 3.4F to 3.4E.

Touhou 2 (Story of Eastern Wonderland) with CanBe / Cereb / PC-9801-118 Sound Sources

The second touhou game has a patch, but that patch was not included on the game disks. It took me a while to find it, but it can be downloaded from here. Run the program (or extract it; 7-zip will do it like an LZH file) and then copy the files into your Touhou 2 install folder. Then start the game by running GAMECB.BAT.

Touhou 3 (Phantasmagoria of Dim.Dream) and 5 (Mystic Square) with CanBe / Cereb / PC-9801-118 Sound Sources

These games came bundled with a canbe patch version. Just run canbe.exe (or manually extract with 7-zip, like with Touhou 2) and run the unpacked GAMECB.BAT to launch the game, just like with Touhou 2.

Touhou 4 (Lotus Land Story) with CanBe / Cereb / PC-9801-118 Sound Sources

Touhou 4 is just like 2, 3, and 5, except for some reason it doesn't use a self-extracting executable, so you have to have LHA installed on your PC-98 to unpack it or else use 7-zip to do it. The files inside work the same way, though.

You can also use LHE to unpack LZH files. lhe CANBE.LZH . will unpack the file to your current directory.


Japanese MS-DOS Help

Unfortunately, even here, you can't escape from Microsoft's eternal stranglehold on operating systems. But NEC's MS-DOS is kind of different from western MS-DOS.


SEDIT: NEC MS-DOS's Built-In Text Editor

How you use this changes kind of wildly between versions. Basically I just run sedit [file to edit] so I don't have to figure out how to load a file, and then saving and exiting differs. I think on DOS version 5 it's F1 followed by 'S' to save, and maybe 'Q' to quit. On DOS 3.3 I just hit f10 and choose the top item in the menu to both save and quit. I usually use "JED" instead, which is English and also feels more emacs-y.



Here's some advice on caring for your PC. This extends to less exotic old computers, too, but contrary to what some people seem to think about 1980's Japanese build quality, it's still made by mortals and suffers from the same problems everything else has - although maybe to a lesser degree in some cases.

Just looking online for listings of PC-98's will show you that a lot of them are rusting, for instance. Leaky Nickel Cadmium batteries are also a deficiency shared by many other computers from the period. Would I trust them more than an average Commodore product? Yeah, probably. But it's not really that hard to have better longevity than a Commodore 64's PLA or power supply, in the grand scheme of things, and so it isn't saying much.

This will include advice on both things you can do to prevent catastrophe, and things you can do so that when catastrophe strikes, you might be prepared for the eventuality and have the things you need to resurrect your computer.


Preventative Maintenance: Back Up Your BIOS ROM('s)!!

(ROM Dumping)

It's a very good idea to take the ROM chips out of your PC-98 and make copies of them, if you have the equipment to do so. That way, it's easy to create replacements for them if the originals fail. One of my friend's PC-9821Ce2's has an EPROM-based BIOS in it, whereas the others look to be mask ROM. But I suppose those could be one-time-program EPROM's as well. OTP chips are also vulnerable to bit decay over the years just like EPROM's are. They're the same chips that are inside of EPROMs, but without the quartz crystal window in the chip "packaging" (outer shell). The window is meant to let light strike it when erasing is desired. Those are brown or purplish usually because they use a ceramic casing rather than a cheaper plastic one so that they can accomodate an erasing window.

But there's a problem with this simple physical approach: I actually can't figure out where most of the ROM chips are on my 486GR! I haven't checked the underside of the motherboard yet, but nearly all the chips I thought could have been ROM's seem to be SRAM's, according to the internet. I was able to find one EPROM, in a QFP format, on its CPU card. I really hope that I've just overlooked them, and the rest are not buried inside one or more of Epson's ASIC's. ASIC means (Application-Specific Integrated Circuit. Basically they are single purpose chips that have functionality endemic to one or a handful of products and which typically perform hyper-specific tasks that wouldn't make sense outside of the specific equipment they are installed in). If they are, it might be a good thing - if it's mask ROM. But if it's not mask ROM, I really hope it doesn't give out. I am guessing it's mask ROM, if they were confident they got everything more or less right. Especially since they were already having custom chips made for this thing anyway. I can't imagine a mask ROM was that much extra to stick on a chip die with some other logic stuff.

Regardless, though, if you don't want to pull out your EPROM programmer (or if, like me, you do not have one…), there is software that seems to be able to make okay dumps of BIOS ROM's. You can find its source code in the repository for the Neko Project II Kai emulator, in the np2tool directory, in the file GETBIOS.ASM. But it's probably easiest to use an existing binary build of GETBIOS.COM instead.

The readme file for Neko Project II Kai implies that GETBIOS.COM is supposed to be a part of the np2tool zip file, but it clearly isn't, so you can instead grab it from this user's page on, as linked to from another, older Neko Project II Kai page which can be found here. You might as well back up everything else using those other tools on the page, too (specifically, MAKEFONT).

Move your program(s) onto the PC-98 using whatever means are necessary. I suggest a floppy diskette or Gotek with a flash drive, but a hard drive could also work if you have another computer with an appropriate disk drive interface to connect it to. Make sure you have as much free space as possible on your floppy disk, if you choose that route. The font ROM is rather large.

A BIOS dump in progress on my PC-486GR.
By the way, this is how you're supposed to be making your ROM files for use with Neko Project II (and some other emulators as well).

I'd love to share my dump with you here, but I am probably not allowed to do that, legally speaking. Don't like it? If you live in an ostensibly free country, maybe write to your representatives and pray for a miracle. Because unless theyu stop representing the interests of capital and start representing you, it's going to take a miracle for entrenched companies to do a complete 180 on this of their own volition.

Maybe someone else out there in a country where it's legal to do so will make and share a copy of the 486GR ROM's some day; I hope that happens. Because I'll likely be dead or nearly 100 years old by the time the Epson's BIOS is public domain, and I'd guess most EPROM's and flash memory will have rotted away by the time my current country lets it go.

Oh yeah; Steamboat Willie is public domain, now that anyone who remembers seeing it in a theater is dead. So have fun with that, guys! Only 73 more years to go for the Epson ROM's…!

That copyright was around before I was born, and it'll still be around when I'm dead and buried in all likelihood. So It's unlikely I'll ever be allowed to share it while I'm breathing. You'll probably have to ask my next of kin and hope that they've kept it. Assuming that they haven't also kicked the bucket yet.

Huh? What's that? You think I'm sounding a little bitter? Whatever would make you think something like that? Copyrights that last longer than human beings are only sensible. I for one pledge allegiance every day to our benevolent corporate hegemony– and to the Free Market,™ for which it stands.


I can at least give you my checksums. I hope they're useful to you - Maybe if you get your own Epson, or your own PC-9801-86 sound board, it'll be good for comparing.

Disclaimer: This is not a "proper" ROM dump for the BIOS. That may require me to remove an EPROM from the CPU card on my Epson (assuming that's what that EPROM is) and dump it directly out-of-circuit. I think that ROM contains more than what the programs I used are capable of, so they would not be good enough for the MAME project, probably. I have neither an EPROM programmer to read it nor a proper QFP chip puller to safely remove the IC.

Note that I have the distinct feeling most of these program authors were not targeting Epsons when they wrote their ROM dumpers, so we just have to hope Epson implemented theirs identically to NEC's.

The 86 sound ROM matches the checksum of the one in MAME's source code. The 26 sound ROM matches the checksum of the Epson PC-486MU's sound ROM in MAME's sources, so they must use the same ROM and I am therefore guessing that the sound ROM is correct. Does it sound different than a real PC-9801-26K card does? Maybe! - or maybe they just omit the NEC copyright string from the Epson 26 Sound ROM.

The font ROM does NOT match the checksum of the 486MU one in MAME's sources. But I've managed to find out that the 486MU's typeface actually just differs slightly. Someone hooked me up with a dump, which I immediately deleted after verifying this. I don't seriously think Epson is about to complain about that; not after they've erased almost all mention of the 486GR's very existance from their site.

Picture: The multiplication sign/asterisk (*) character at
                    0x0AA3 differs between the PC-486GR and 486MU. This
                    difference is one of several.
In the top left corner of each document panel, you can see how the asterisk (*) character is different between the
486GR and 486MU ROM's, but also that both are valid. There are other little differences here and there.
Viewed in 1bpp, row interleaved.

Epson PC-486GR BIOS ROM Checksums

$ (for file in BIOS.ROM SOUND.ROM SOUND_26_486GR.ROM FONT.ROM; do
echo "$file"':'
printf 'CRC32:\t '; crc32 "$file"
printf 'MD5:\t ';   md5sum < "$file"
printf 'SHA-1:\t '; sha1sum < "$file"
printf 'SHA-256: '; sha256sum < "$file"; echo; done
) |sed 's/ -.*//'

CRC32:   9c4807a1
MD5:     5db6205995036a8c034015f28d8e62df 
SHA-1:   22a9027352e926cc64dea59d8e4011749380d9f9 
SHA-256: 95c319bf81533c8ee9cf7f93b75ef0d6aaa8565f384b9c584c6e45cf2c1d8d85 

(**Note: NEC's PC-9801-86 sound card; on-board Epson 26 sound ROM disabled in BIOS settings**)
CRC32:   80eabfde
MD5:     42c271f8b720e796a484cc1165ff4914 
SHA-1:   e09c54152c8093e1724842c711aed6417169db23 
SHA-256: f05b508d49f31f2a1a61724f013572592abc0833c09c45a72180e84247dc0d0d 

(**Note: Integrated "26 sound" ROM; removed 86 card,re-enabled 26 sound in BIOS, then re-dumped**)
CRC32:   6cdfa793
MD5:     a77fc2bc7c696dd68dba18e02f89d386 
SHA-1:   4b8250f9b9db66548b79f961d61010558d6d6e1c 
SHA-256: 53a7db5388de3ffe8dc746d7dffde0da4fda951bf2c80a3f981308d120c06215

CRC32:   e18f4529
MD5:     d890c89b099879b962b759fd0839aa91 
SHA-1:   900025caec5e4e6758eb7fcf8e29bb90686399d2 
SHA-256: 0c6879c5aac25265ab332763e639409b003af0567ba7d4de483c88f09cd18634

Notice how if you have an onboard sound source, its rom must be dumped with any other sound card removed and after making sure the internal source is re-enabled in your BIOS or DIP switches.

While and after doing this, make sure there's no corruption on the floppy disk you're using to move the files to another computer, since unlike with most things, corruption in your BIOS ROM backup could be disastrous if you ever need to restore it and you find that your only copy was destroyed by a bad floppy disk.

You might laugh, but I had this happen the first time I tried making a backup. Later backup attempts seemed to work better (using different media). I also did the second backup attempt using my hard drive and then copied from the HDD to the FDD after doing the dump so I could perhaps compare more easily. And of course, that way I have a copy backed up on the HDD, which isn't too bad of an idea to begin with. Just a little more redundancy if things go south.

You might want to run the MAKEFONT program from that site, too, while you're at it. It'll generate a FONT.BMP file, which contains all of the font in a human readable picture format. I haven't figured out how to convert FONT.ROM into the FONT.BMP format (it seems to be compressed in some way), and some emulators use FONT.BMP instead of FONT.ROM. Also, it's just neat to see the whole font, and having it in a more human readable format is another plus.

Other ROM's

You might have other ROM's in your system. Some kinds of C-Bus cards (including some sound cards) have them, for instance; my SCSI controller is one of these. I don't know of a tool to dump roms from these cards, although one very probably exists. Maybe a linux boot would be enough to get access to them, sort of like how I can dump my newer PC's VGA BIOSes from /sys/. That's something I should probably try. It might or might not work; the steps that work for dumping my VGA BIOS option ROM are shown on here on

By the way, an "option ROM" is IBM's terminology for any accessory card or hardware that contains a ROM that is supposed to be accessed by the computer's main processor(s). It's an old piece of terminology, contemporary with phrases like "PC compatible," "IBM Compatible," and so on. IBM's marketing jargon was "Options by IBM," and IBM used that word instead of "accessory" a lot of the time. Your IBM PC didn't get accessories or expansions; it got options.

Anyway, I just think it's neat that that little fragment of 1980's PC terminology has just barely held on still; even UEFI systems support loading from ROM's. That said, they have to be crafted differently than old style BIOS ROM's, and aren't compatible. Microsoft's documentation still calls them UEFI option ROM's, though!

On the IBM PC platform, a SCSI controller or other device that requires boot initialization or can control the computer from very early on is still readable after boot. Assuming the PC-98 doesn't do something very strange with some bus arbiter or something, I don't see why one wouldn't be able to dump, for instance, a SCSI boot ROM without resorting to an external piece of dumping hardware. I have yet to try this because I have been able to find dumps of my cards' rom's around the web already and I am thus less worried about immediately backing mine up... Although I still should.


Known Problem Models

Capacitor failures

For the PC-9801/PC-9821 series computers, I mainly have heard of problems with the "A-MATE" series, which I believe consists of the following models:

With98 (see links) doesn't seem to consider the following to be "A-MATE" series machines. I am assuming that is because the following machines have window accelerators built-in and are therefore sort of "post-apocalyptic" as far as DOS goes.

There's at least one guy I've seen online in the Anglosphere who has a 9821An that he had to replace a bunch of caps on, too. So I guess maybe it's just that all of the A series are maybe likely to have bad caps.

The problems mainly seem to be capacitors going bad, primarily in the power supplies. I get the impression that they may also have problems with early surface mount electrolytic capacitors going bad, since people often speak of them in the same sentence as they talk about later-model Sharp X68000 computers (which I believe also had motherboard capacitor issues).

I also bought an 86 sound board which all the caps had leaked on. THAT was fun. I could get the barest semblance of audio out of one side with my speakers cranked to max, and nothing from the other. I got a second one that was already recapped for entirely too much and the one in need of recapping sits until I have a hot air soldering station. It seems that at least some 86 sound boards had the same issue as the A-series computers (which also used surface mount electrolytic capacitors).

In general, it's a good idea to replace capacitors in all old electronics one gets, but I don't really always follow my own advice. Capacitor failures might just cause a problem that can be fixed by replacing the capacitor, but they can also cause cascading failures where more stuff fails, either immediately or after a short delay (if the cap isn't immediately replaced). Even if the device appears to continue working, if you hear a POP coming from your electronics, don't ignore it. I just can't afford to follow it, but seriously if the wrong capacitor(s) pop I might be looking for a whole new computer or CRT or whatever, or buying a lot of parts other than capacitors to fix what just broke. Please, please, please consider recapping your stuff, if you can afford to and have the time to. I know some repair places will also do it for you. There's a local shop that rebuilds speakers where I live that also can do recap work for people. Maybe you have somewhere like that you can ask around at?

It should also be said that the "A" series models are considered quite good when they're in working condition. They're more easily expandible than the Ce2 and Cs2 systems are, with a socket so you can upgrade CPU's and an extra C-bus slot, and they are at least as featureful, with Integrated 86 sound and all of that good stuff. So if you can do the work, or if you can get it done by someone, they might still be a great choice.

Do note that the A series mentioned above might not be capable of touhou in stock configuration, but with a CPU upgrade it could be pretty good for that. Make sure you factor in that cost when deciding, should you be invested in playing the Touhou games. Deriving from the information in ZUN (the developer)'s readme file, You'd want at least 66MHz to play it. That means a 2x multiplier 486DX2 or equivalent if your computer has a 33MHz bus, and 3x+ multiplier 486DX4/Am5x86/Cx5x86/whatever else I'm forgetting about for a 25MHz bus one.

I think it may be possible to convert a 25MHz bus computer into a 33MHz bus one by replacing a "crystal" (quartz-based oscillator) on the motherboard, but I don't know if other things might need changing. And you'd defintely have to know how to solder to even try that.

The Touhou Problem

See also: Touhou Project Notes

The Touhou games present a special challenge, if you want your old DOS game compatible system to also be able to run it at a good speed.

The Ce2 and Cs2 (and the stock 486GR, for that matter) are not ideal if you want to play Touhou, since the Ce2 and Cs2 have no CPU socket (they have a soldered-down 486SX only). If you were very good at soldering and had the right tools, you could of course replace that with a different one by soldering it in. Or look for a pretty uncommon accelerator board that piggybacks on top of the soldered-down CPU. I haven't seen one of them for sale in months. The 486GR, several other Epson models, and most of NEC's "A" line (and maybe B line?) have CPU sockets.

So What Should I get?

If you don't need Touhou, then almost definitely a 9821Ce2 or 9821Cs2. They are in a sweet spot for compatibility with older stuff and having 86 sound built in. You may also consider a 9821Ce or 9821Cs (sans 2); those have a 486 ODP socket on them. The downsides are that the Ce and Cs are older, and only have two C-bus slots, and use SCSI drives (both optical and hard disk) internally... and SCSI stuff tends to cost more. If you keep a hard disk inside, then that means you won't need a C-bus card for that, so I'd say both slots would likely be filled by an 86 sound card and a MIDI card, if it were me.

But with that being said, I have been told by a Japanese native(?) that the Ce (not Ce2) has an "NEC check" in its onboard SCSI controller; that means it might not let you use non-NEC hard drives and/or optical drives if they're connected. That kind of ruins a lot for me. So I'd suggest a Ce2, either an Epson model with an 86 sound board + SCSI controller, or a Ce2/Cs2. Or A-MATE series if you are prepared to replace every electrolytic capacitor on it.

If you have a computer with an ODP socket instead of a normal one, then you either need to ground the extra pin on the socket and use a normal CPU or pay the silly prices for an "overdrive" 486 with the extra pin on ebay (can be over four times the cost. Sure, the ODP's have write back or whatever... but I suspect half of it is just people not wanting to solder a wire to the motherboard).

My friend got three Ce2's and a Cs2, all untested, and all of them more or less worked. One had a bad optical drive, and they all needed their floppy drive heads cleaned, and one had a hard drive that had had a head crash, so that needed replacing, but since they use IDE that's not as painful as it can be with SCSI drives. And the motherboards and power supplies all worked just fine, So maybe they've actually aged better than the A series did?

If you need Touhou and also other DOS games, get a recapped A-MATE (one of the PC-9821Ap* models from the list above), or any 25MHz or faster 486-class PC-98 or Epson 98 clone with an ODP socket that you can put a 486DX4 into. You will also need a voltage converter board or you might fry the DX4 when you put it in.

If you ONLY need Touhou, get either a 9821 C166/C200/C233 "cereb," or a PC-9801-118 sound board plus a V166/V200/V233 "ValueStar" and then use the "CanBe" sound patches for the games. These have a 166 to 233 MHz Pentium MMX CPU in them, and will provide a VERY smooth experience with minimal slowdown. Information on the "CanBe" patches can be found in the "Touhou Project Notes" section on this page. You may even have a superior experience to anyone who uses any kind of 486. Even MIDI in Touhou 2 can work if you change the address of the GamePort in the BIOS without needing any more boards. But you'll have to use a joystick-to-keyboard adapter if you want to use a gamepad or MSX/Atari style Joystick.

The ValueStar models do not have a YMF288 on board for sound, so you will need to get a PC-9801-118 card or solder a YMF288 to the board yourself (and possibly support circuitry).

You could even get multiple PC-98's; one Ce2, one Pentium-class for Touhou, and maybe even a third PC-98 (like a 9801V* or 9801RA) for very old games that run best on an NEC V30 CPU. Most stuff runs fine on a Ce2, though, so the third might be optional.



I bought a PC-9801-86 sound card that was covered in capacitor leakage and didn't work properly when plugged in. Be cautious, especially when surface mount type capacitors are involved. They are hard to desolder safely with an iron (without ripping up traces/solder pads), and early ones love to die. Upon desoldering, they will smell strangely like fish. A hot air station is recommended (to maximize the smell of fish).

As far as I can tell, both my Epson and my friend's PC-9821 Ce2's/Cs2's are using only through-hole capacitors on their mainboards - so you should be safe-ish with those. But it's still always a good idea to replace old capacitors, even if I don't practice what I preach.

Additionally, the PC-9821 A* series computers seem to have problematic capacitors in their power supplies rather frequently. I would suggest replacing all capcitors in those, if you go for one of them. Or find a PSU that was already recapped (probably expensive).

If you ever turn your computer or monitor on and hear a loud BANG or a popping noise, you probably just blew a capacitor. Even if everything appears fine, you probably should immediately stop using the computer until you've either found the popped cap or replaced all of them. All of them is better, but it's both kind of expensive and quite labor intensive, and I get that. I'll still recommend you do it, but the one thing you definitely should avoid is continuing to use the computer after a capacitor blows. Eventually, things operating out of spec like that can cause more cascading failures that are possibly much harder to repair.



There are two main ways corrosion strikes in a computer, in my experience. One is case or RF shielding rusting, and the other is corrosion on the circuit boards.

PCB Corrosion

A lot of PC-98's I see for sale suffer from some degree of rusting on the shell. This is annoying, but if not severe then it's probably fine. For more information, if you have case rust and it bothers, you, you can read more about it later in this section.

The very real problem is that of battery leaking and PCB corrosion. Earlier models are probably more likely to have Nickel-Cadmium barrel batteries, which are a bane to pretty much anyone who wants to use a vintage computer. They WILL leak out, eventually, even if yours looks fine - but probably yours has started leaking already, if you have such a battery.

Luckily my 486GR and my friend's CE2's do not have those batteries; they use a rechargeable lithium coin cell instead. If yours has a NiCad barrel cell, though, clip it off at once, wipe some vinegar around where it was, followed by some alcohol to get the vinegar off. (…NiCad's are alkalinic, right??)

Anyway, if the corrosion hasn't crept far from the battery's spot on the board, you are lucky. Sand the corrosion off to expose good copper, repair traces if corrosion has left no good copper behind in those spots. After some alcohol cleaning, let it dry and then paint over the exposed copper with nail polish or similar to replace the solder resist which used to cover the copper that you removed. Then, get a new NiCad cell - but solder wires into the main board where the battery used to be, and mount the battery itself somewhere on the casing or otherwise isolated from the PCB as much as possible. That way, when it leaks next time, it hopefully won't pour its copper-eating contents all over the circuit board.

If your corrosion is bad, you may need to do more intensive sanding and scrubbing and soldering, or perhaps even just replace the board. Hopefully, you won't have to do that.

As mentioned in a previous section, the other thing that can cause corrosion is capacitors leaking. This is by far the most common with old surface mount capacitors; many PC-9801-86 sound cards seem to have leaked capacitors which leave this sort of blue-green residue on the board. This stuff is nowhere near as caustic as the NiCad battery leakage, but it's still definitely not a good thing. If your PC has these (my 486GR does not, nor do my friend's Ce2's and Cs2), and you see leakage or your computer is acting weird, then get a hot air station as soon as possible and remove all the surface mount caps (after documenting where the caps were, what their capacitances were, and what their voltage ratings were). Buy new caps and put them on. Early surface mount capacitors just kind of sucked in pretty much everything people put them in.

Desolder the caps in a well ventilated area!!! - the smell is awful. The electrolyte, when heated up sufficiently, smells of bad fish. No; I am not kidding. It truly is a 'fish' smell!

Once desoldered, clean off board of residue again (I forget once again if the electrolyte is alkalinic or not... either jump straight to the alcohol, consider deploying the vinegar first if appropriate). You will probably find that soldering surface mount caps is easier than desoldering them.

I do NOT recommend that you desolder the surface mount caps with a regular iron. Maybe it's possible - but all I've succeeded in doing that way is ripping up traces at least half of the time.

Hopefully, if your PC is not a laptop/notebook model, and it's old enough to use a 486 CPU or older, then it won't be using many (if any) surface mount caps. I don't know how common the problem is on PC-98's, but it impacted a lot of later Amiga models for sure, as well as X68000's and possibly FM Towns computers. I have a friend with two Amiga 4000's; one still needs recapping. (Wish he'd just let me have the damn thing.) Sega's Game Gear is also rather famous for pretty much universally needing all new capacitors at this point.

I think Nintendo's Game Boy used some SMD caps on the CPU board, if I remember correctly... but for some reason, I haven't noticed leakage there yet. If so, then that's curious. I could of course be wrong, and conflating it with the later consoles like the Game Boy Pocket or Game Boy Color - by which point surface mount caps had seemingly improved somewhat.

I sort of expect this won't be a problem for most of you, except for maybe if you go for a very late PC-98 or have some problematic expansion cards.


Case Corrosion

This is by far the lesser of two evils. If it isn't getting worse, you an probably leave it alone. Or, if it's not too far advanced and you feel a little brave, you could maybe even try to remove it yourself. I've never tried on a PC, but I don't see why what I'm about to discuss wouldn't work the same as it did on my last car (a 1993 Volvo 240 wagon).

You could probably just go to an auto parts store and buy some prepping chemical like what's used to clean rust off of a surface before painting POR-15 or similar protectants onto an area of a car body. The prepping stuff is nasty; be sure you don't let it get on your hands. Wear thick rubber gloves. Seriously. You'll probably be sorry if you don't.

I think the one I used was POR-15 branded, but basically you just want a solvent that can dissolve rust and leaves the good steel behind. You don't need the special paint itself (the thing they tell you to paint on once all your prep work is done on your car) if you aren't planning on sticking your computer it in a swamp or other humid area afterwards.

But that stuff will absolutely chew through rust. If the rust hasn't penetrated the metal, then it could be worth a shot. Just be aware that if the rust has penetrated all the way through the case, the prepping agent will tunnel a nice little hole right through the steel where the rust spot used to be.

If it's just surface rust, though (it likely will be, since computers don't usually get as much exposure to adverse weather and salt as cars), then you can absolutely try it. It was really cool when I did it on my car to just watch the rust disappear and leave the gray steel behind. If someone other than the POR-15 company sells it, they probably sell the prepping agent cheaper, so definitely look around before buying any. Don't just take my advice as a plug for that brand. I just bought what was readily available locally.



I've had to fix one thing on my Epson that broke after I got it while I was working on a circuit to let me use a joystick to simulate keypresses by manipulating the circuitry of an original keyboard. If I ever get that working I'll add the diagram. But for now, I'll mention that my problem was that the keyboard stopped working altogether; everything else about the Epson continued working.

I opened it up, and on the underside of the motherboard there was a small one-amp surface mount fuse near the keyboard connector that, when measured, showed a resistance of about 0.75 megaohms (it should be close to zero). So I knew that the fuse had blown. I stole a 1 amp surface mount fuse from a dead Playstation I had sitting around from years ago, and the keyboard worked again when I put the whole thing back together. So if you're having keyboard trouble, maybe you've got a blown fuse?

I have since been told by a Japanese PC-9801 user that the Epson models are also known for blowing that fuse when hot-swapping keyboards (swapping without turning the computer off first). That's not what I did to blow it, but it's probably a good thing to be aware of as well.


It can be hard to find information and remember where it is with the PC-9801/9821 and compatibles. This is my attempt to compile some of the sites I find myself accessing that contain useful tidbits.

There has been some attempt made to sort these by significance, although it's hard to rank a lot of them. You should treat the first few in each language section as as required reading when figuring out how you want to have your PC configured/what parts you need. The rest are mostly good for things like solving issues after getting the system, or finding documentation on DIP switch settings on C-Bus cards.

These are pages primarily in the Japanese language, usually if not always maintained by Japanese authors. If you can read Japanese, or are just looking at a table, you may not even need to run it through a translator. But these days, translators are somewhat good, so if you are struggling, you might as well try one.

Thankfully, with tech specs, things are often in English or katakana transliterations of English words. I've found it to be good practice.

[J] With98: PC-9800 Series Information (Must read!!)

 Topics: NEC, Epson, Specifications, General Information

This site contains a comprehensive list of most if not all PC-98 models (including Epson clones) released in Japan. It also contains system specifications, information on model variants (information like how the PC-486GR2 came with no hard drive, or what OS a computer came installed with). It will also tell you information like how much RAM the computer can be upgraded to use, how much RAM it shipped with, the release date, and oftentimes even the dimensions of the case and weight (which is handy to know for purposes of estimating shipping costs).

It is also useful for checking if a PC-98 model you are thinking of buying contains undesirable chips on the circuit board, like a Windows focused accelerator (if you want DOS games, you don't probably want this).

[J, EN] Basic NEC PC-98 Information Archive (NEC PC-98 基本情報 書庫目録)

 Topics: NEC, MS-DOS, Programming, Peripherals, Pinouts, DIP Switches, Boot Key Commands, Technical Information, Memory Locations, Digital Signalling

This is a great site if you are technically minded or are looking for things like electrical diagrams. It goes into a lot of detail on a lot of things, and has some pages in English (but most are in Japanese).

I'd say that if I had to pick one site to find technical details of the PC-98 architecture itself, this would be it. It even explains details that would be useful if writing an assembly program for the PC-98, as well as details that would be useful if you were to try to write an OS.

It probably holds the most value for programmers, but you don't have to be an OS developer to get useful information from the site. It just has generally useful info, like how to add memory. If you have to tinker with the hardware, it's just worth a look. Especially if you're thinking of making your own external floppy drive enclosure/adapter or similar.

[J, En] NEC PC98 Basic Reference (English) (Must read!!)

 Topics: NEC, Hardware, Part Numbers, Specifications, Architecture, Addon Boards, Jumpers, Pinouts, General Information

Contains a lot of basic information that will be useful to most PC-98 series hardware users (and perhaps emulator users as well). Includes some very nice pages with descriptions of interrupt settings and so on for cards, and lots of info on the 26 sound and 86 sound boards. There are more pages available in Japanese on this same site that cover additional topics.

[J] EPSON PC-486GF/GR/GR+/GR Super modifications

 Topics: Epson, CPU, Motherboard jumpers, Using >14.6 MB RAM on GF/GR

This page was a gem for me. It's the only place I've seen any of the on-board jumper settings for the Epson PC-486GR and relatives described. It looks like the models differ mainly in CPU installed, but also have jumpers differently configured to accept more memory. Additionally, the 486GF needs to have its 32MHz clock crystal replaced with a 50MHz one if you want to turn it into a 486GR!

[J, EN] "Shiunten" Museum(?) - 試運転の資料館

 Topics: NEC, Epson, Pinouts, Part Numbers, Electrical Implementation Details

I am not sure on the full details of what this site actually is, but I was able to successfully use it to find some information on the pinouts of my floppy disk drives and some other connectors on my Epson. It has a lot of pinouts listed for parts of the PC-98 platform computers in general.

A couple of the pages are available in English, such as "Connecting an FDD for PC/AT compatible computer to PC-9821 (Overview)", which might be useful when your disk drives die.

I used the site to get pinouts for the Epson floppy drives, but there are lots of non-floppy things too on the pinouts page, even stuff for other systems like the Playstaton. A pinout for the external floppy drive connectors on the PC98 and Epson models also is provided!

[J] Workshop Memories(?) - 工作室の記憶

 Topics: NEC, Epson, Pinouts, Adapters, DIP Switches, Hardware Maintenance

This is another site detailing pinouts and some DIP switch settings for some PC-98 related hardware. Lots of cable adapter wirings are also provided.
If I recall correctly, it also details how to disassemble and clean a floppy drive.

[J] Expansion Boards and Extensions for PC-98: DIP Switch Setting Documentation Page

 Topics: NEC, DIP Switches, C-Bus Boards

Another page from the above site; just an easy link to it.

[J] Packen Software - PC-9801 Expansion Boards

 Topics: NEC, DIP Switches, Music, C-Bus Boards

A page focused on sound cards for the PC-9801/9821 and compatibles that was the only place I could find documentation on the DIP switches for the Roland MPU-PC98II MIDI C-Bus board. Also has docs on some FM cards.

The Main Page also covers other topics outside the realm of the PC-98 series.

[J] 5ch: EPSON 98 Compatible Machine Thread (Part 7)

 Topics: Epson, Hardware, Miscellaneous

This is part of a series of threads discussing the PC-98 compatible Epson computers; I've found a lot of valuable information in this series of threads. It's where I discovered the Epson FDD terminal mode, as well as a lot of other stuff.

[J] Repairing NEC PC-9801-86 YM2608 Board

Contains nearly anything you'd want to know about repairing a PC-9801-86 "86 sound" card/board. It seems a lot of them if not all of them have surface mount capacitors, and they like to leak and destroy everything. Recapping (replacing capacitors) often fixes these issues. Contains a list of all the capacitor values and ratings that you will need to do the job. Note that this job is much easier with a hot air station, and much less likely to result in ripping pads off the board.

Lainblog - Soykaf: Writing PC-98 Floppy Images Under Linux

 Topics: Floppy Disks, Floppy Disk Drives, Floppy Disk Writing, Linux, 360RPM, 3-Mode Drives, 1.2MB disks

This is just a one-off blog post, as far as I know, but there's a chance they have other posts, too.

This person's blog post helped me to understand how to make a floppy disk work on a PC-98. Even if you are just preparing western IBM-formatted floppy disks so that your PC-98 can read and write them, or are trying to copy files to the PC-98, it's good information to know.

In brief, some 3.5" floppy drives can run at 360 RPM - many USB ones, but not as many internal western ones, if any. The PC-98 traditionally used 360 RPM, even for 3.5" disks. In this mode of operation, a 3.5" diskette is accessed exactly like a 5.25" diskette, as far as the drive or computer is concerned. But for this to work, your floppy must first be sectored and formatted as if it were a 5.25" disk. Most western 3.5" floppy disks will not be from the factory - they'll be IBM formatted, which for high density floppies means 300 RPMs and 1.44 megabytes of data instead of 360 RPMs and 1.2 megabytes. If your drive and software supports it, you can transform an IBM formatted floppy into a PC98 formatted one. Also, some later PC-9821's (perhaps 1993 or 1994 onwards) can natively handle 300 RPM 1.44 megabyte diskettes in addition to their historical 360RPM DD and HD formats.

PC-9821 Cheat Sheet

 Topics: NEC, DIP Switches

This one covers a bunch of things, most prominently translations of the DIP switch setting descriptions for one particular PC-9821 model. They might vary a little for yours, but especially if you have an NEC model (rather than an Epson) it helps quite a bit with figuring out what you are looking at.

NFG Forums: "NEC PC-9801 - How to Partition & Format an HDD?" - Archived

 Topics: MS-DOS, NEC, Epson, Installation, Hard Disks, Hard Disk Formatting, Hard Disk Partitioning, Hard Disk Initialization

This one is an invaluable resource, since the hard disk initialization process isn't quite the same as the one you may be used to from western DOS. Someone's gone to the trouble of taking lots of screenshots to guide you through initializing and formatting a fresh HDD for booting DOS from. It saved me a lot of time. It specifically is describing the process in NEC MS-DOS 6.2 (which can also be run and installed on an Epson PC-98; it doesn't have the "Epson Check" sabotage some earlier versions of NEC MS-DOS do).

Useful Search Terms

Can't find what you're looking for above? Here's some words that might be handy to put into search engines. For the "how to type" row, I am using the "romaji typing method" in Anthy on Linux, but I think it should work similarly on Windows with Microsoft's input method editor. Also, the spaces in the "how to type" field are merely there to aid in mapping the keystrokes to the individual japanese characters. If kanji are involved, you will need to press 'space' after inputting that group of characters and select your kanji.

This maybe wouldn't be necessary if typing the hepburn pronunciation worked. But 'small kana' and such have to be entered differently.

A '※' character (Japanese reference mark) means I was too ignorant and/or lazy to figure out how to type something. Sorry in advance. In such cases, if a typing guide is still provided, it means that it was my best attempt and it came close or sort of worked but added extra junk characters.

I just include it in the hopes that it may help someone who is trying to learn Japanese - even if many or all of the words here are just katakana transliterations of English.

English Japanese Romaji
How to Type
DIP ディップ Jippu (Dippu) di xi xtsu pu
Switch スイッチ Suitchi su i xtsu chi
Keyboard キーボード Kiiboodo (Kībōdo) ki - bo - do
Mouse マウス Mausu ma u su
Monitor モニター Monitaa mo ni ta -
External 外付 Sotodzu ※(so to) (tsu ke)
Drive ドライブ Doraibu do ra i bu
Cable ケーブル Kēburu (kay-buru) ke - bu ru
Terminator ターミネータ taamineeta (tāminēta) ta - mi ne - ta
Floppy フロッピ Furoppi fu ro xtsu pi

This list is by no means comprehensive. It just contains some useful phrases/terms off the top of my head that I searched for while getting parts. A lot of things can be searched without this, like "HDD" (Hard Disk Drive), "FDD" (Floppy Disk Drive), and many other abbreviations. Usually, you will not see periods between the letters in those abbreviations.