FBE2h Dk'tronics Real Time Clock - Z80 PIO Port A Control
FBE3h Dk'tronics Real Time Clock - Z80 PIO Port B Control
FBE8h Dk'tronics Real Time Clock - Control port for RTC chip (4bit latch) '''(details unknown)'''
Port B is connected directly to a standard 9-way connector on the left of the interface.