8442, Z8442, Z80SIO2 Z80 dual async/sync serial I/O (bonding option #2). +--------------+ D1 |1 +--+ 40| D0 D3 |2 39| D2 D5 |3 38| D4 D7 |4 37| D6 /INT |5 36| /IORQ IEI |6 35| /CE IEO |7 34| A0 B/A /M1 |8 33| A1 C/D VCC |9 32| /RD /W_RDYA |10 Z8442 31| GND /SYNCA |11 SIO-2 30| /W_RDYB RxDA |12 29| RxDB /RxCA |13 28| /RxCB /TxCA |14 27| /TxCB TxDA |15 26| TxDB /DTRA |16 25| /DTRB /RTSA |17 24| /RTSB /CTSA |18 23| /CTSB /DCDA |19 22| /DCDB CLK |20 21| /RST +--------------+ [This information is part of the GIICM]