Leonardo meets Emu42

[Massimo Gnerucci]

(09-17-2021 09:40 AM)J-F Garnier Wrote:  I'm happy that at least a few people are appreciating the Leonardo and Plato ROMs !

Some background on extracting the ROM.
On Christoph's site, you can read: " For [low-end and mid-range Pioneer] calculators you need special hardware and knowledge to extract the data from the Saturn bus system, a way, as far as I know, never gone on a Saturn based calculator".
So it was considered as "almost" impossible.

The 32S is, as I mentioned several times, my preferred every-day calculator rather than the 32SII, and it was a pity that the 32S was not supported in Emu42 due to the lack of ROM.
Some weeks ago, maybe stimulated by the SM projects, I investigated how to extract the ROM from the 32S.
I used an old 32S, partially working (usual kbd issue) that I opened long ago, and carefully looked at the PCB.
Quite quickly I noticed some 10 unused tracks that end to test pads and are not used elsewhere on the PCB.
I had the idea that maybe these test pads were bringing the Saturn bus outside, then with the help of some information from Christoph, I was able to identify the function of the test pads, access the internal Saturn bus and read the ROM. And that’s it !
The needed hardware is actually nothing special: a simple Arduino board is well enough.



J-F

Excellent job! Thank you both.