Found these inside a non-working 71B

[Paul Berger (Canada)]

For testing you don't need to cut anything as long as there is no HPIL module installed. Pin 9 (Dout) from #5 in your diagram by default goes to the HPIL port. The wire that you soldered into the via under the resistor taps into that connection, just connect it to 8 (Din) on the back RAM and leave 9 (Dout) on the front RAM unconnected. Taking another look at your diagram you could just remove the connection from 9 of the the front RAM and you should be OK as long as there is no HPIL module installed.

If you wish to make this permanent, or mount a module in the top left, where you found the math module.

The memory will show up as system RAM, when memory is converted to port RAM an identifying signature is written at the beginning of the memory in the module, and since RAM is volatile, when you power it on, the contents will be random.

Paul.