== I/O Ports ==
  FBE0h  Dk'tronics Real Time Clock - probably Z80-PIO Port A Data (RTC Data bus)  FBE1h  Dk'tronics Real Time Clock - probably Z80-PIO Port B Data (General Purpose 8bit I/O Port)  FBE2h  Dk'tronics Real Time Clock - probably Z80-PIO Port C (unknown purpose)A Control  FBE3h  Dk'tronics Real Time Clock - probably Z80-PIO Port B Control
  FBE8h  Dk'tronics Real Time Clock - (unknown purpose)
Not sure if above addresses are correct, for example, A0 and A1 may be swapped...? PIO Port A seems to be the plain RTC Data Bus, there should be also RTC Read and Write signals, which are maybe found in one (or both) of the '''unknown purpose''' portsport?
== Software ==