8420, Z8420, Z80PIO Z80 parallel I/O. +--------------+ D2 |1 +--+ 40| D3 D7 |2 39| D4 D6 |3 38| D5 /CE |4 37| /M1 C/D A1 |5 36| /IORQ B/A A0 |6 35| /RD PA7 |7 34| PB7 PA6 |8 33| PB6 PA5 |9 32| PB5 PA4 |10 Z8420 31| PB4 GND |11 PIO 30| PB3 PA3 |12 29| PB2 PA2 |13 28| PB1 PA1 |14 27| PB0 PA0 |15 26| VCC /ASTB |16 25| CLK /BSTB |17 24| IEI ARDY |18 23| /INT D0 |19 22| IEO D1 |20 21| BRDY +--------------+ [This information is part of the GIICM]