Diagnostics, Loopback connections – Texas Instruments 4000M User Manual
Page 249
Loopback Connections
The serial and parallel communications tests in the
Diagnostics Program offer optional loopback tests that
require placing loopback connectors on the output ports of
the computer. The loopback connector pin assignments are
listed in the following tables.
Loopback Connector Pin Assignments
Serial Loopback Connections
Parallel Loopback Connections
DB9 Pin
Signal
1-7-8
CD-RTS-CTS
2-3
TX-RX
4-6
DTR-DSR
DB25 Pin
Signal
15-2
D0-ERR
13-1
STRB-SLCT
16-10
INIT -ACK
17-11
SLCTIN-BUSY
14-12
A
UTOFEED-PE
Diagnostics
Diagnostics D-11