Challenges

This page lists the past contests, challenges and other events that I’ve participated in and written about on this weblog.

You can find more of my repair work and homemade hardware on the main page.

RetroChallenge, October 2022 (RC2022/10)

A year after the last one, I entered into the October 2022 RetroChallenge with the goal of doing some preservation work for the NEC mini5 word processors. I wanted to dump and archive a copy of Tetris that I found for the platform, as well as start the process of getting the system into MAME.

A Mini5 Hello World

Yes, it is finally time to sit down with the mini5HA again. My goal was to figure out how to make a working program for CP/M using its built-in assembler, and I wasn’t going to give up until I had at least a “hello world.”
Roll the Tape

The NEC Bungo mini5 PWP-5SX Japanese word processor that I’ve been working on this month came with an instructional VHS tape explaining how to use its near-infinite multitude of features. Here’s how I captured that tape.
NEC's Tetris Processor

Tetris is a classic time-waster, both in and outside of the office. What good is any computing device if it can’t play this game? Tokyo System House certainly thought so, and ported it to the NEC mini5 line of CP/M-based word processors. Let’s preserve it for future generations and then see what it’s like!
The Case of the Dead Mini5SX

In order to get a copy of Tetris for the NEC mini5 series of word processors, I had to buy it along with a whole word processor set from the previous owner. This LCD-based mini5SX is sleek, attractive, surprisingly heavy, and broken. Very, very broken. Let’s see if we can fix up this grey beast, and dump its ROMs.
Mini5 Word Crusher

Used Japanese word processors have been a tempting siren for me for years, but I’ve avoided them so far due to the huge shipping weight and my general illiteracy in the language. What if those word processors could run CP/M and had a CRT? Ah, now that’s a different story.

RetroChallenge, October 2021 (RC2021/10)

For the October 2021 RetroChallenge, I entered into the “Publish It!” category with the intent to finish up the Leako ColecoVision-compatible game console and release the files.

This entry was a prize winner!

Make Your Own ColecoVision At Home (Bonus Episode - The Real Thing)

Through the more-than-generous offer of a ColecoVision, I now have a real machine to use as a basis for comparison. Just what is the real machine like inside, and could it possibly be better?
Make Your Own ColecoVision At Home (Part 4 - Quadrature Controllers)

We got conventional ColecoVision “hand” controllers working well in the last entry. I’ve never used any of the ColecoVision’s more exotic controllers before; will they work properly on my clone machine, even though I didn’t really understand them?
Make Your Own ColecoVision At Home (Part 3 - Joystick Fix)

In the last entry, I was left with a working ColecoVision-compatible board, albeit one with a very stuttery controller that would only work when connected to what I thought was the second controller port. Let’s fix that, and then enjoy the cheapo ColecoVision games that I spent all this effort building this thing for in the first place.

RetroChallenge, September 2018 (RC2018/09)

For this event, my goal was to get my PC8801mkII equipped with a Gotek floppy emulator, and some form of colour video output. I was successful, and got the PC98 to have a floppy emulator as well!

The last ride of PC88 colour video

After a respin of the PC88 colour video board, the PC8801mkII now has excellent digital colour video out.
A mystical journey to PC8801mkII colour video

I’ve been using the monochrome video cable on my PC88 ever since I built it. Colour video was a little more complicated, so I ended up designing a bunch of adapters to try and get it to work. I’m happy to announce that one of those adapters has finally worked!
PC98 - New floppy board, sound 'fixed,' more testing

Now that the PC98 can load a game off a flash drive, there’s a lot more parts of it I can test. Today, I spent a few minutes putting together a new revision of the floppy board and inspecting the computer.
Floppy adapter board works for the PC98!

After I designed the first version of my PC88 floppy board, I thought it would be fun to put one together for the PC98 as well. Why do I need an adapter for a computer that already has 3.5” floppy drives? The PC9821AP2 I own has a 26-pin floppy drive connector, like a mid-90s laptop, and most standard IBM PC style floppy drives have 34.
Revenge of the PC-8801mkII floppy adapter board

In the last entry, I found myself with a working adapter board to allow a 3.5” floppy drive (like a Gotek) to work with the NEC PC8801mkII. This liberated me from having to source, organize and maintain 5.25” floppy disks, and opens a large library of software for this computer without having to hunt through the used market. However, like all good things, there were a lot of bugs with the old adapter.
PC-8801mkII floppy adapter board

I wanted to get a Gotek working on my PC88, and after seeing that there were a lot of Japanese hobbyists who had managed to get an HxC floppy emulator working, decided it must be possible - even if not simple.

RetroChallenge, April 2018 (RC2018/04)

I didn’t have a specific theme for this event, and just took it as an opportunity to try and get as many machines in my hoard up and running.

SparcStation 1+ - have keyboard, will error

In a previous installment of the SparcStation 1+ saga, I got the machine to present a serial console to one of my other old computers, but couldn’t get any video out of the video card or boot to an actual operating system.
Super Famicom Repair-O-Rama!

I bought a large lot of Super Famicoms off of Japanese auction for cheap, and set about trying to repair them. Almost all of them had problems.
The C64 is alive!

A power supply arrived from Ray Carlsen, and it works great. I spent the time while I was waiting by soldering a really bad video cable. I only managed to melt one DIN plug in the process!
Building a keyboard adapter for the early PC8801. (Part 1 - Research)

If all goes well, I will soon be the owner of an NEC PC-8801mkII “Model 30.” The platform is famous in Japan, as later models of the PC88 featured a ton of independent games, including many from developers who would go on to create games that were popular worldwide (Thexder, Snatcher and Ys all got their start on this platform). It also has a lot of trash, but neither of these things are interesting to me right now. I’d be happier just getting the computer to work (not least, because as a non-SR mkII, there are very few games I can enjoy on it anyway).
Reassembling the Amiga 2500, Part 1 - Hard Card

Things are starting to get hectic again with real life, but there was still some time recently to work on the Amiga 2500. My objective was simple: get the machine back together into a working box again so it is no longer spread all over my workbench.
Commodore A501 memory expansion battery removal

When I first got my Amiga 500, it wouldn’t boot. Suspecting something was wrong with the A501 512K memory expansion, I pulled the card, at which point it did boot. It didn’t take me long to realize that battery corrosion had killed it.
SparcStation 1+ - setup

My streak of actually trying computers that are in my pile continues with this SparcStation 1+. While it has been a very loyal and very handsome monitor/keyboard stand for the last few years, it would probably be more interesting as a functioning computer.
Commodore 64 pickup

I picked up a Commodore 64 off the local classifieds. It came with a 1541 floppy drive, a bag full of blank floppies and tapes, the C64 itself, the infamous black finned power supplies that kill C64s, a Rixon modem, and a Nortel multi-line keyset from the 90s.
Amiga 2500 keyboard refurb

The keyboard I got with my Amiga 2500 had:
- A broken right alt key,
- A spotty (at best) return key,
- And a numpad enter key that wouldn’t stay up, but did work,