OPCOM is an acronym for OPerator COMmunication mode. In this mode the ND-110 CPU console (terminal no. 1) communicates directly with the microprogram. This mode is used for service and maintenance only.
Pressing the OPCOM button puts the CPU in OPCOM mode. When the CPU is in OPCOM mode, interrupts from the console are disabled. Data from the console goes directly to the microprogram. OPCOM mode is terminated by pressing the escape (ESC) key on the console.
- Norsk Data Document ND–06.026.01 ND-110 Functional Description Chapter 7.1 Control Panel + Glossary