IBM X.25 - Manual (Page 26)

Pin Assignments
X.21 Connector Information
The X.21 pin assignments for the 37-pin connector on the PCI
co-processor adapter and the corresponding pin assignments for the
15-pin connector on the optional adapter cable are listed in
Table 3-1. (The pin positions on the connector are shown under
“Pin Numbers” on page 3-1.)
Table 3-1. X.21 Interface Pin Assignments
Signal
Name 37-Pin
Connector 15-Pin
Connector
GND 7 8
T (A) 10 2
C (A) 11 3
R (A) 12 4
I (A) 13 5
S (A) 14 6
T (B) 28 9
C (B) 29 10
R (B) 30 11
I (B) 31 12
S (B) 32 13
3-2 X.25 Co-Processor PCI GTO