Mark/Space Polarity Selection Switch (8-Port Asynchronous Mil-Std 188 Adapter Only) - IBM RT User's Setup Manual

Mark/Space Polarity Selection Switch (8-Port Asynchronous MIL-STD 188
Adapter only)
6-40 Options Installation
Use the following diagram to set mark/space polarity for Ports A
through H on each 8-Port Asynchronous MIL-STD 188 Adapter; an
an opened paper clip or ball-point pen can be used to set the
switches.
A.TZIF204