Vintage Computing

An MCP bridge from Claude Desktop to MAME gave the model a full development loop on a 1981 TI-99/4A: write TMS9900 assembly, compile a cartridge, launch it, look at a screenshot, try again. It knew the memory maps and VDP registers cold. It had never run a single instruction on the hardware.

That gap showed up fast. Direct memory writes came back mangled by the datamux, a bus width converter the documentation mentions but never warns you about. A green backdrop came out purple because the console's own startup routine was fighting the code. A dozen iterations later, the logo was on screen in light red, since the 15-color palette has no orange.

The machine already worked fine on its native 68000, the built-in 1.3 ROM, and Workbench 1.3. That's charming from a historical perspective, but I never built the cable to get RGB into my odd Sony display, and I'd like something a bit newer under me before I start playing with old graphics software and drawing tablets.

So: a piStorm standing in for a much faster 68000, and an rgb2hdmi board sending video out over HDMI. Both are part of a whole world of Raspberry Pi projects for reviving retro computers, and I've barely scratched the surface of what they can do. Here's where things stand so far.

Someday there will be a proper writeup, and probably a video. For now, a placeholder: an archived message from an Amiga BBS in which Joe Smith explains how he got a Sony KV-25XBR talking to an Amiga, after discovering that nobody at any computer store, any Sony dealer, or Sony customer service knew where to find the cable.

He bought the service manual, decided the official PX-34 connector was overpriced and the SMK-0001 cable a gamble, and wired up his own breakout box instead: a 9-pin Amiga video connector, six RCA jacks, and two switches for sync-on-green and TV audio. The full 34-pin and 9-pin pinouts follow, along with the reference links he gathered.

Another project that makes me go, wow. LumaCode reads the luma signal coming off old computers and game consoles and carries it as digital video data, which an external upscaler can then turn into something a modern monitor or TV will actually accept.

The clever part is where the cost lives. The little board that generates the LumaCode signal for a given machine is simple enough to be made cheaply, so every system in the closet can have one. The expensive piece, the upscaler doing the real work, sits at the other end and gets shared by all of them.

This one has been sitting since we moved into the house, and I've finally had time to get back to it. The plan was to run Kickstart 3.1 with an adapter board to make it play nicely with this revision of the motherboard, which got me a black screen at boot. Putting the 1.2 ROM back in got me a yellow screen instead, which is not much of an improvement.

Then, somehow, I zapped the machine and everything came up working. Strange, but I'll take it. The floppy drive tests fine, so what's left is sorting out the keyboard and building a cable for analog RGB.

I have the case of a Mac Cube sitting around waiting to become a Linux box, and I keep eyeing the 2013 trash can Power Macs going for almost nothing on eBay. There are a lot of fun weirdo machines out there, and the Macintosh's 40th anniversary seemed like a good excuse to round up my favorites.

Every machine here was manufactured and sold to the public, so no prototypes and no what-ifs. Together they show off Apple's inventive streak and its willingness to gamble on odd shapes and odd ideas. Weird is a matter of taste, of course, so if I've missed your pick, say so in the comments.

A few months' worth of hardware purchases, gathered into one video: a Commodore4ever power supply to replace the old brick, a new monitor, a PenUltimate+ cartridge, and a selectable RAM expansion with a reset switch for the VIC-20. All rad.

Then a drive up to Funspot in New Hampshire, home to one of the largest collections of classic arcade games anywhere. Rows and rows of cabinets, most of which I am spectacularly bad at. Music from Mattie Maguire, The Basic Game, and Falcon Dives, and thanks as always to everyone supporting the channel.