It took me a long time to post the promised schematics. I am really sorry for the delay. Here are the schematics and PCB design. Now I am going to look for the programming file for this baby on my old backups. As soon as I find them I will post the .Hex files. The only thing I can tell you about this design is that it has been tested for a few years and it is perfectly stable and reliable.
I found a backup with an old version of the firmware's source code (the one that I was using before changing the parallel keyboard into the PS/2 keyboard for local control). If I can't find a newer version I will modify this code but only if somebody is interested. It's been a long time and maybe there is no interest in this old project anymore. PS/2 keyboards are not common place nowadays either. It would be nicer with Bluetooth communication to a tablet or laptop...
Reply with Quote
