Some quick (bad) news. I got the LS240 (they're actually HCT240, compatible), installed it, fired a test PC with some games on it. The test PC is a 386-40 (the CPU is a TI486DLC) with 16MB RAM and a microdrive for HDD. I only tested with Secret of the Monkey Island (EGA version plus MT32 patch).
I tested it first with keropi's Music Quest clone and my MT32(old style). Works fine with the default settings I/O=330, IRQ2.
The HardMPU board that I built however doesn't work. The MT32 doesn't receive a signal. I used the same settings: IRQ2 (jumper on the first pair in the IRQ block) and I/O=330 (jumper on last pair in the I/O block). I checked that the MIDI_out signal goes to the correct pin on the output connector (pin6 on the DB9F) as is the case with my under-the-pcb-mounted connector. I used thus the same breakout cable as for the Music Quest clone.
Troubleshooting tomorrow, it's late now. I'm bummed.
ab0tj: is the Atmega chip supposed to stay cold? The one on my PCB does, even after 10 minutes powered up and supposedly playing music. The Zilog CPU on the MQ card gets pretty warm. But then it's a completely different beast.
I/O, I/O,
It's off to disk I go,
With a bit and a byte
And a read and a write,
I/O, I/O