ibm6580.cpp (IBM Displaywriter) WIP. Thanks to nigwil@vcfed for redumping the ROM.
Character generator ROM is not dumped (and it's in EBCDIC), I've used a generic PC font + translation table. Actual font looks like this:
I'll see what I can do wrt dumping all the roms and the microcontroller. Not having the floppy one is probably a showstopper, I'm guessing the protocol isn't obvious. Are you going to add the blinky diagnostic leds? Can you push what you have so far so I can compare the dump with what I end up doing?