Changes
/* Technical */
== Technical ==
Uses a Z80 PIO, MM58174 RTC, 6116 (2K RAMSRAM), 4040 (12bit counter for sequential SRAM addressing), and 32.768kHz Crystal(for the RTC). Both RTC and RAM are backed by rechargeable 3.6V NiCad battery. Used I/O Ports are (with only A10,A4,A3 decoded):
FBE7h ACU Real Time Clock Z80-PIO Data In/Out Port A
Bit7..4 SRAM Data7..4
Bit3..0 SRAM Data3..0 and 4bit RTC Data
FBEFh ACU Real Time Clock Z80-PIO Data In/Out Port B
Bit7 SRAM /CS and /OE (0=Select)
Bit6 RTC /CS (0=Select)
Bit5 RTC /RD (0=Read)
Bit4 RTC /WR (0=Write)
Bit3 RTC Address A3 and SRAM /WE (0=Write)
Bit2 RTC Address A2 and SRAM Address Counter RST (1=Reset, 0=Active)
Bit1 RTC Address A1
Bit0 RTC Address A0 and SRAM Address Counter /CLK (1-to-0=Increment)
FBF7h ACU Real Time Clock Z80-PIO Configure Port A
FBFFh ACU Real Time Clock Z80-PIO Configure Port B
