serial interface cable The RS-232 on the C64 is a little bit strange. It uses inverted TTL level of signals. The RS-422 ports on the Macintosh has both an inverted and non-inverted input By using the inverted instead of non-inverted the inverted C64 level is back to normal
8 pin mini-DIN male
connector to the Macintosh
24 pin DZM 12 DREH
connector to the C64 UserPort
| Mac | C64 |
|---|---|
| GND+RXD- | 4+5 |
| RXD+ | 8 |
| TXD+ | 6 |