I like to repair old X68000 machines, and have been thinking about making a test IPL for running hardware tests.
I threw together one of these with Claude, and it seems to work really well. It even managed to diagnose an issue I wasn’t aware of in my X68000 pro.
The repo is at https://github.com/buffis/x68k-testipl
To use it, burn the IPL in bin/ to EPROMs for your X68000 IPL slots.
What this does
When starting the machine, this replaces the stock IPL (BIOS) with a systems test. Optionally, you can compile the Test IPL to boot into a real IPL once the system tests have completed. The default files in bin/ in the repo DOES NOT contain any Sharp IPL data, so you will have to supply that yourself if you want to do the chaining.
It will do some simple communication with various onboard peripherals, as well as run a memory test. See the repo for more details.
Finding an issue with the RTC in my X6800 Pro
When trying this out, I noticed that the RTC Oscillator test was failing. Turns out this was a real issue, and time was not advancing. Some quick investigation showed that the variable capacitor near the RTC was busted.
A NFG thread mentioned that just adding a fixed capacitor there should work as a replacement, so I did that, which both fixed the actual issue, and made the test show green in the IPL. Nice!
The bodge wire is due to me fucking up a trace when violently removing the original capacitor. Bit of a fuckup, but this machine has seen worse.
