Thanks for posting here!
We had a short discussion about your converter on
Deskthority just yesterday.
Yours looks like a very cool solution with the advantange that it can be used fully extern, without even opening the historic keyboard. And I would probably even be able to build it, because there's no SMD soldering involved.
I'd also like to know more about how programming the controller works. I think the ATMega has an EEPROM -- do you take the chip out and put it in a programmer if you want to change something?
How did you cope with only three keys that send break signals? I'm not sure if I understand how you programmed the modifiers. Do you use one of the shift keys as Control? Or did you define shortcuts in the adapter for just some common Linux CTRL combinatons and have no way to use others?
I just bought an 3278 two weeks ago, and have one of
xwhatsit's controllers on its way to me. His approach is different (and more intrusive), he completely replaces the controller and uses an ATmega32u2 to convert to USB. He also posted in the thread that I mentioned. Very exited to get my hands on one.