@EFF8.ADF TTL Async Adapter
TTL Async Adapter
TTL Async Adapter P/N 94X0836 "TTL ASYNC CARD", Japanese design
F1 fuse for 5V supply
J1 female DB9 connector
U15 NS8250AN / INS8250AN UART
Y1 1.8432 MHz osc
The rest of the card is filled with through-hole 74xx logic.
All adapters I've seen had the same exact assortment of bodge wires on the
solder side (see here).
Note: As the name implies the I/O signals use
TTL levels (0-5V) - not RS-232 compatible (+/-12 or 15V)!
This adapter can be found in many PS/55 5560
machines where it's used as an interface for the CADAM keypad.