8530, 8531, Z8530, Z8531 Zilog Serial Comminucations Controller. Z8531 has no synchronous capabilities. +--------------+ D1 |1 +--+ 40| D0 D3 |2 39| D2 D5 |3 38| D4 D7 |4 37| D6 /INT |5 36| /RD IEO |6 35| /WR IEI |7 34| A0 A/B /INTAK |8 33| /CE VCC |9 32| A1 D/C /W_REQA |10 Z8530 31| GND /SYNCA |11 SCC 30| /W_REQB /RTxCA |12 29| /SYNCB RxDA |13 28| /RTxCB /TRxCA |14 27| RxDB TxDA |15 26| /TRxCB /DTR_REQA |16 25| TxDB /RTSA |17 24| /DTR_REQB /CTSA |18 23| /RTSB /DCDA |19 22| /CTSB CLK |20 21| /DCDB +--------------+ [This information is part of the GIICM]