HP-32E with errors ...

[PANAMATIK]

(04-29-2021 10:24 PM)ThomasF Wrote:  BTW, do you know if it is easy to read out the contents from these Spice ROM's? I suspect they are serial ROMs, but checking the schematics, it might work to build a simple reader with a PIC or a Arduino maybe? It would be really satisfying to be able to find the actual fault and repeat the error in an emulator - at least just for fun!

If you know how to do it, it is easy. I did read the ROMs of some SPICE calculators in 2015 with a PIC processor, which sent serial data to a PC while reading the ROMs.

In this thread Post #123 I describe how I read the HP-31E and HP-33E ROMs by invoking STO ENTER ROM test and reading the ISA 56-bit serial addresses and data. But I know from analyzing the STO ENTER function, that the ROM test will be stopped prematurely if the checksum fails. Therefore you have to use another method: disconnect at least the ISA pin from the processor and inject your own address signals.

Bernhard