Casio fx-5000F Scientific Calculators: parallel computing made simple

[SeanRiddle]

(10-07-2019 10:45 PM)jebem Wrote:  

(10-03-2019 03:47 AM)SeanRiddle Wrote:  I came across your post while searching for info on the OKI M5268. That chip is actually a ROM that uses the same interface as the HD61914 SRAM (and Panasonic MN6404 ROM). I assume the calculator requires more ROM space than the HD62001 has internally, so they had to add an external ROM. If I can find an inexpensive Casio fx-5000F on ebay, I'll see if I can dump the ROM.

If it is a rom, and it makes sense now, then the processor seems to be a 4 bit and not 8 bit as I especulated initially.

I bought a Radio Shack EC-4023, which is an OEM of the fx-5000F. I was able to dump the ROM from the M5268, and I decapped all the calculator chips and took pictures: http://www.seanriddle.com/m5268.html