You can get that and a few other things here:
EPS16+ schematics don't exist anywhere I have access to. SD-1 ones do but I lost my copy, I'd need to email the guy who gave them to me
Can you point me to the EPS and ASR-10 ones?
The display/keyboard controllers (they're usually the same chip) are either a 6500 (a 6502-based micro controller) or a 68HC11. They're not documented outside of the schematics showing which GPIOs on them are connected where.