KY11-LA Operator's Console

The KY11-LA Operator's Console was the standard basic front panel for the PDP-11/04 and the PDP-11/34; it provided only the functionality to halt or reboot the machine, not the then-usual full functionality of a conventional 'lights and switches' front panel.

The controls were:

• A three-position power switch ('DC On', 'DC Off', and 'Standby' - in the latter, power was supplied to the MOS main memory only)
• A 'Halt'/'Continue' two-position toggle switch (in the first position, the CPU was stopped)
• A 'Boot'/'Initialize' spring-loaded toggle switch (normally in the 'Boot' position, in which is did not have any effect; setting it to 'Initialize' caused the machine to do a power-fail restart)

It was normally used with the M9301 ROM card, which could be configured to 'grab' the CPU on on a power-fail restart, and which contained (among other things) a console emulator.

It consisted of a front panel which included a small circuit board; to perform the basic functions of the console, it communicated with the PDP-11 CPU through a 10-wire flat cable connected to the main backplane. In addition to several standard UNIBUS signals (SACK, INIT, DCLO and ACLO), it also used a pair of additional backplane lines (Halt Request and Grant) to communicate with the CPU, to request that the main CPU halt, and for the CPU to acknowledge that it has honoured that request.