The battery is charged while the computer is switched on. The data will be retained for several months even if the computer is not used during this time.
Uses a Z80 PIO chip to control the HD146818 RTC chip via port A. Do not use Port A as this will affect the RTC operation.
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)
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)'''
Do not use Port A as this will affect the RTC operation. PIO Port A seems B is connected directly to be a standard 9-way connector on the plain RTC Data Bus, there should be also RTC Read and Write signals, which are maybe found in left of the '''(details unknown)''' port?interface.
== Software ==