Started work on this but didn’t have much time to finish it.

It’s a Teensyduino port of the multiboot serial converter for use on the Gameboy Advance.

Sorry, I’m terrible at programming. Here are the sources (includes the two originals)

MSMCcable-1.02

Edit 1/11/10: Resumed work on this. Figured it didn’t work because I used the delayMicroseconds function rather than a hardware timer which didn’t give enough resolution. I also fixed the passthrough problem. Once I finish learning how to use hardware timers, I shall get back to you.