FBE0h Dk'tronics Real Time Clock - [[Z80 PIO]] Port A Data ([[PC compatible RTC chip|HD146818P]] RTC Data bus)
FBE1h Dk'tronics Real Time Clock - [[Z80 PIO]] Port B Data, used for external control (General Purpose 8bit I/O Port)
FBE2h Dk'tronics Real Time Clock - [[Z80 PIO]] Port A Control(do not use as this will affect the RTC operation)
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)'''