Digital Output Port Connector - IBM 7220 Instruction Manual

Appendix B, PINOUTS
B.3 Digital Output Port Connector
B-2
Figure B-3, Digital Output Port Connector
8-bit TTL-compatible output set from the front panel or via the computer interfaces;
each line can drive 3 LSTTL loads. This connector mates with a 20-pin IDC Header
Plug. The pinout is as follows.
PIN # FUNCTION
1 GROUND
2 GROUND
3 D0
4 GROUND
5 D1
6 GROUND
7 D2
8 GROUND
9 D3
10 GROUND
11 D4
12 GROUND
13 D5
14 GROUND
15 D6
16 GROUND
17 D7
18 GROUND
19 +5 V
20 +5 V
D0 = Least Significant Bit
D7 = Most Significant Bit