Commodore SX 64 CPU Board
- only two versions known (to me) 251102 Rev A and 251102 Rev 1, I can’t see any differences.
- contains the CPU, memory, VIC, SID and Rom’s of the SX.
Integrated Circuits
| PCB Identifier | Chip Number | Remarks | Memory Location/bit |
|---|---|---|---|
| UA3 | 74LS257 | Do not use TI or NS | |
| UA4 | 4164 | DRAM | D7 |
| UA5 | 4164 | DRAM | D5 |
| UA6 | 4164 | DRAM | D3 |
| UA7 | 4164 | DRAM | D1 |
| UB1 | 74LS258 | ||
| UB2 | 74LS373 | ||
| UB3 | 74LS257 | Do not use TI or NS | |
| UB4 | 4164 | DRAM | D6 |
| UB5 | 4164 | DRAM | D4 |
| UB6 | 4164 | DRAM | D2 |
| UB7 | 4164 | DRAM | D0 |
| UC1 | 74LS139 | ||
| UD1 | 2332 | Character ROM | $D000-$DFFF |
| UD3 | 2364 | Kernal ROM | $E000-$FFFF |
| UD4 | 2364 | Basic ROM | $A000-$BFFF |
| UD7 | 6510 | CPU | |
| UE3 | 6581 | SID | $D400-$D7FF |
| UE4 | 82S100 / 906114-01 | 906114-01 PLA | |
| UE7 | 2114 | RAM 300NS | |
| UF4 | 6567 | VIC | $D000-$D3FF |
| UF6 | 7408 | ||
| UF7 | 7406 | ||
| UG6 | 4066 | ||
| UG7 | 555 | Timer |
Schematics
Board Image
