jdd's gemini thing

1998 Computer Project, Part 2

<2022-02-06 Sun>

[continued from Part 1]

Hardware

I get a kick out of making things, whether they be gemlog entries, paintings and drawings, software, or in this case, a computer. Note that this is true even when the result is not very good or very useful, and I'll admit I sometimes stint the planning phase in order to get to the fun, making part. However I have to admit the kick is greater when the result isn't terrible, and I've found stopping to ask myself exactly why I want to make the thing does tend to improve the result.

I've already gone over some reasons in the previous installment, but to recap the main goals here were to:

1. cater to my nostalgic whims by building a desktop computer like the one I had in the second half of the 90s, and

2. appease my frugal Dutch ancestors by making it actually useful in the present day, not just a self-indulgent folly

Externals

Initially I wondered whether it would be possible to build a retro-looking desktop with all new parts, including case, keyboard and monitor. And after doing some research I concluded ... yes, more or less, except for the monitor. For example, Evercase in the UK does make some rather retro looking cases [1], or perhaps the Checkmate A1500 would fit the bill [2]. And of course, Unicomp continues to make a version of the classic IBM-style Model M keyboard.[3] For a modern monitor ... well you might be able to get one with a white bezel, or possibly one with a 4:3 aspect ratio, but nothing with quite the clunky solid feel I was looking for.

However, when I came across a very broken vintage 1998 computer headed for the e-waste/scrap pile, that seemed to be a sign I should approach this a different way. I mean, no point spending good money on a new case when you can get a perfectly good case for free, right? No worries about whether it really has an authentically retro look. And given the sorry state of the insides, no guilt about gutting it, either.

Shortly thereafter I lucked into a very good deal on a real IBM model M keyboard, and a Viewsonic LCD with the right look, even if it wasn't exactly the right vintage. It was lacking a power adapter, but guess what's still available on Ebay? A 'sleeper' build it was to be.

Internals

As mentioned in part 1, my desktop computing needs are relatively modest. I don't do fancy media production stuff, play contemporary video games, or otherwise tax the hardware very much. I might run a VM or two, now and then, but typically even these tend to have modest RAM, processing, and storage requirements. Think Ubuntu server, or MS DOS 6.22. I do play some older games (Bioshock, Portal 2, Half-Life 1 & 2), but none of them have onerous hardware requirements, by contemporary standards anyhow.

Early stage build

All of which is why the following list of parts is a bit on the low-end side:

I chose the motherboard for its low cost and decent selection of older ports, primarily VGA and PS/2.

Note the absence of a graphics card. As graphics cards are hellishly expensive these days I went with integrated graphics, thinking I could upgrade later if I needed to, and if prices ever dropped. Well, my monitor is a 20 year old VGA LCD with a maximum resolution of 1280x1024. So far I have not felt the need to upgrade.

The StarTech adapter turns a 3.5" drive bay into a bay capable of housing two 2.5" SSDs. Currently only one of the slots is occupied, by the 1TB WD Blue. It amuses me that the matching 3.5" bay right next to it hosts the floppy drive, with its whopping 1.44MB capacity. Speaking of which ...

Floppy Drive

It was clear from the outset that the computer would need to have an internal floppy drive. Not because I would ever use it, but because floppies are iconic - quite literally in fact, lingering on into the present day as the save icon. And for that reason, you can't really build even a faux late 90s PC without one. True, the iMac G3 (1998) didn't have a floppy drive, but as I recall that was a rather controversial move on Apple's part. I had no wish to court controversy here.

And the floppy drive would have to actually work. I know, some sleeper pc builders just leave them in for looks, not hooked up to anything. A useless vestige of an earlier time. But that just seemed wrong to me, for purely aesthetic reasons.

Problem being, no one makes internal floppy drives anymore. And I'm not sure anyone ever made one that hooked up to a SATA connector. Remember how in Part 1 I waxed enthusiastic about how so many hardware standards of the 90s (and even late 80s!) have survived into the present day? That's not as true of the internal connectors, where everying transitioned to SATA and PCIe in the oughts. Given that floppy drives were being phased out at exactly the same time SATA was being phased in, It's either difficult or impossible (not sure which) to find one that would work with a modern motherboard. Not to mention modern mobos lack the controller circuitry necessary to communicate with the drive.

Testing the ArduinoFDC

There are solutions out there, however. It was just a matter of figuring out which one would work best, for my particular version of best. A Kryoflux or Supercard Pro could both connect to the motherboard via onboard USB, as did the solution I eventually settled on, David Hansel's ArduinoFDC [4]. The ArduinoFDC is a nifty little project that, as the name implies, turns an Arduino microcontroller into a floppy disk controller running a very tiny, limited DOS to allow reading and writing of data, simple directory listing, creating and deleting directories, etc. The Arduino connects to the floppy drive via a bunch of jumper wires. You communicate with the Arduino from the main computer via serial connection over USB, using a client like PuTTY or minicom, and use an old-school protocol (XMODEM) to transfer files back and forth. It's not terribly efficient but I never said the floppy drive had to work /well/, only that it had to work. And nothing says "retro" like XMODEM.

[Parenthetically, I will note that David Hansel is also responsible for a number of other cool "modern retro" projects, including the amazing Arduino Altair 8800 simulator, available in kit form (the "AltairDuino") from Adwater & Stir [5]. I am a big fan].

Fortunately, an internal standard that /has/ stood the test of time is the venerable molex connector. On my power supply there is only one of them, but one is all you need to power the floppy drive.

The floppy drive has the distinction of being the most interesting, the most useless, and the most inelegant part of the build, all at the same time. To mount the Arduino in the case I drilled holes in a plastic lego block to match the case mounts, and more holes to match the Arduino mounts. I then attached the Lego block to the case, and attached the Arduino to the Lego block.

In the next installment, we'll look at the software build.

[Part 3]

Links

[1] Evercase

[2] Checkmate A1500

[3] Unicomp

[4] ArduinoFDC

[5] Adwater & Stir

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1998 Computer Project, Part 2 was published on 2022-02-06