First post, by ab0tj
So, we already have the very awesome SoftMPU for intelligent MPU401 operation. But some people (like myself) for some reason prefer a hardware solution. So, here is my idea. Create a port of SoftMPU that runs on a microcontroller, and put it on an ISA card. Instead of the port trapping technique used in SoftMPU, read and write directly from the ISA bus. And, instead of using the UART MPU on a sound card, use the UART on the microcontroller to directly send and receive MIDI data. Basically an MPU-401 clone that should in the end cost under $100.
Creating the hardware wouldn't be very difficult with a microcontroller that has enough GPIO pins. But I may need some help with the firmware, or even better if someone who is a better programmer than I stepped up to write the firmware. I would want to keep it open source so the community can build their own, but also maybe offer PCBs and/or kits for sale to the community.
It's just a crazy idea I've been toying around with. Would anyone actually be interested??
UPDATE 8/22/16 - HardMPU seems to generally work at this point. Bug reports and new code are welcomed. SysEx delay works differently than SoftMPU due to not being able to block the host machine's code execution like SoftMPU can. The delay seems to work for games that need it, but breaks others (that don't need it anyway). You can find the current code and binaries here: https://github.com/ab0tj/HardMPU/
UPDATE 2/7/18 - I generally don't have time to make kits or built boards available "to order" right now, but I do have bare boards available (PM me) and will be listing built boards on a popular auction site as I have time to build them.