Disponibile su Commodore C64/C128.,Software emulato. Il segnale e' a livello TTL e non RS232, e RXD/TXD sono invertiti. Trattasi della User Port, usata come una RS232..
Commodore USER PORT
| Pin | Name | RS232 | Description |
|---|---|---|---|
| A | GND | GND | Protective Ground |
| B+C | FLAG2+PB0 | RxD | Receive Data (Must be applied to both pins!) |
| D | PB1 | RTS | Ready To Send |
| E | PB2 | DTR | Data Terminal Ready |
| F | PB3 | RI | Ring Indicator |
| H | PB4 | DCD | Data Carrier Detect |
| K | PB6 | CTS | Clear To Send |
| L | PB7 | DSR | Data Set Ready |
| M | PA2 | TxD | Transmit Data |
| N | GND | GND | Signal Ground |