SCSI 是 Small Computer System Interface 的縮寫，外置式 50 針接口的外觀為母插座：
連接電纜插頭為 50 針公插頭：
|
引腳定義 |
|
Pin |
Name |
Dir |
Description |
|---|---|---|---|
|
1-25 |
GND |
Ground | |
|
26 |
DB0 |
Data Bus 0 | |
|
27 |
DB1 |
Data Bus 1 | |
|
28 |
DB2 |
Data Bus 2 | |
|
29 |
DB3 |
Data Bus 3 | |
|
30 |
DB4 |
Data Bus 4 | |
|
31 |
DB5 |
Data Bus 5 | |
|
32 |
DB6 |
Data Bus 6 | |
|
33 |
DB7 |
Data Bus 7 | |
|
34 |
PARITY |
Data Parity (odd Parity) | |
|
35 |
GND |
Ground | |
|
36 |
GND |
Ground | |
|
37 |
GND |
Ground | |
|
38 |
TMPWR |
Termination Power | |
|
39 |
GND |
Ground | |
|
40 |
GND |
Ground | |
|
41 |
/ATN |
Attention | |
|
42 |
n/c |
- |
Not connected |
|
43 |
/BSY |
Busy | |
|
44 |
/ACK |
Acknowledge | |
|
45 |
/RST |
Reset | |
|
46 |
/MSG |
Message | |
|
47 |
/SEL |
Select | |
|
48 |
/C/D |
Control/Data | |
|
49 |
/REQ |
Request | |
|
50 |
/I/O |
Input/Output |