Found these inside a non-working 71B

[Dave Frederickson]

(03-15-2018 10:12 PM)MikeSD Wrote:  Based on location it looks like OD/HALT I think.

OD and HALT are inputs to the 71 from the front ports. This pin on the CMT module would have to be an input to ID on the module's memory controller.

According to J-F's doc,

http://www.jeffcalc.hp41.eu/files/hhp96k.pdf

grounding the ID pin will disable LCIM and the module will be configured as a multi-chip module.

I suspect that the ID pin affects the LCIM bit on the first or second module only. If the pin is grounded then modules 1 and 2 or 2 and 3 get configured as a 64k port and if not then as three as 32k modules.

So, Mike, you might try connecting a short wire between pins 1 and 11 on the first module and see if you get a single 64k port.

Dave