The Old Computer Challenge started last Sunday. Have been real busy so all I’ve done so far is brainstorming ideas and research. If I had infinite time, I’d consider OpenVMS + CAN bus silliness. CAN bus, a.k.a. controller area network, is used to interconnect bits and pieces of car electronics. (Imagine plugging OpenVMS into your car for diagnostics!) Buuuut, OpenVMS has been hamstrung by HP corporate overlords’ action against the HP hobbyist community. Seemed like a can of worms.
Next ChatGPT and I came up with using DOS instead. The idea is MS-DOS or FreeDOS in QEMU gets encapsulated CAN data over a serial port. A Linux-based glue process then mediates between the QEMU instance’s virtual serial port and SocketCAN or some other CAN interface. Maybe start with a CAN simulator. There’s an open source one which looks promising.
Now the learning and effort gap becomes a bit smaller. I’ve hacked on FreeDOS and DOS before; it’s a fun environment for 16-bit/32-bit x86 assembly programming. A lot more fun than Win32 assembly programming. But, I’ve never worked with serial, so that’ll be the learning. And CAN is new to me.
Spent a lot of time researching specifications. Thanks to some AI training data repository, most of the ISO CAN standards are available “free” “of” “charge”. If I hadn’t found them online, I once requested an IEEE standard via interlibrary loan (ILL) and got my own copy! Yup, somebody sent me a loose-leaf copy of a couple-hundred-page standards document, for free! It’s how I learned about OpenFirmware internals.
I was hoping to get started soone, and as it’s looking, maybe I never start. But the plan remains:
DOS in QEMU ⬌ Linux glue ⬌ CAN simulator or maybe an actual CAN device.
Bonus, could run this stock on Android, make a DOS OBD-II diagnostic tool over CAN. Just plug the Android into the car, fire up DOS, and huzzah, diag tool.
We’ll see. Maybe I stick to learning DOS serial for now, see what I learn.
Unsure how far I’ll get. My own life is in a state of flux and flow. And honestly there’s just important things to do, like helping the homeless near me not die from state oversight. Or maintaining the vehicles that make my lifestyle possible—today I smell like lanolin undercoating and motor oil. All equipment breaks if you let it.
At least I type away on an IBM Model M made around the time I was born. That feels OCC-adjacent in itself!
Figure 1: IBM Model M in a van on a hammock