SCSI-1 uses a 50-pin IDC connector for parallel storage at 5 MB/s, supporting up to 7 devices. Legacy interface found on older servers and workstations.
| Pin | Name | Function | Type |
|---|---|---|---|
| 1 | GND | Ground | GND |
| 2 | DB0 | Data bit 0 | I/O |
| 4 | DB1 | Data bit 1 | I/O |
| 6 | DB2 | Data bit 2 | I/O |
| 8 | DB3 | Data bit 3 | I/O |
| 10 | DB4 | Data bit 4 | I/O |
| 12 | DB5 | Data bit 5 | I/O |
| 14 | DB6 | Data bit 6 | I/O |
| 16 | DB7 | Data bit 7 | I/O |
| 18 | DBP | Data bus parity | I/O |
| 25 | TERMPWR | Terminator power 5V | PWR |
| 36 | BSY | Busy | I/O |
| 38 | ACK | Acknowledge | I/O |
| 40 | RST | Reset | I/O |
| 44 | SEL | Select | I/O |
| 48 | REQ | Request | I/O |
| 50 | IO | Input/Output | I/O |