Changes
/* Technical */
== Technical ==
Uses a [[Z80 PIO]], MM58174 RTC, 6116 (2K 2Kx8bit SRAM), 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)
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
The 4bit RTC Registers are:
0 Not used / Test (W)
