[Radio Wrangler]

I've had a break from it doing a few other jobs.

I've dug out a Philips logic analyser PM3580 in the hope that it might have some support for a Philips/Mullard microprocessor, but it doesn't look like it. A one-chip mask programmed job just has I/O pins and nothing as revealing as the data and address busses make it off the die.

The two-wire connection between the processors is interesting. Both machines have their own clock crystals, so it has to be some sort of handshaked asynchronous transfer, though the data rate doesn't need to be much. I've got some time set aside tomorrow evening to have a dig.

First off is to add some light pull-ups so I can see if the switch matrix is being scanned.

Second is to take a look at inter-chip comms. Considering the age and the paucity of memory space, these things must have been written in assembler so the comms could be anything.

PlanB is to just replace all the available silicon on both CPU boards and hope... well it'll be quick and fairly cheap. Which pushes design-my-own-machine into plan C.

David