Article 163843 of comp.os.vms:
Hello,

i think you mean M7168 VCB02 4-plane module and M7169 VCB02 base module. There
was a documantation with every GPX workstation. Here the base module
switch pack settings:

	S1  Selects address line 3 (0 = on, 1 = off)
	S2  Selects address line 2
	S3  Selects address line 1
	S4  Unused

There are three LEDs (D6...D8).

	------------	      ------   ------
	|    J4    | D6 D8 D7 | J3 |   | J1 |
	------------          ------   ------

When the power self-test is completed the lights are updated to indicate
the status of the subsystem. Here the base faults:

	D6 D8 D7	After power self-test
	0  0  0		No faults detected.
	0  0  1		VCB02 base modul fault
	0  1  0 	First VCB04 4-plane module fault
	0  1  1 	Second VCB04 4-plane module fault
	1  0  0 	Not used
	1  0  1		Keyboard fault
	1  1  0 	Mouse tbalet fault
	1  1  1 	Catastrophic
	
Regards R. Wingert