Changes

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

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?