(SOLVED) 41CL - DOUBLE HEPAX ACCESS and MMU CONFIG

[rprosperi]

(08-24-2019 05:13 AM)Ángel Martin Wrote:  

(08-23-2019 11:09 PM)rprosperi Wrote:  OK, thanks. I was aware of that in the NEWT (which has power and speed to spare), but did not think the HEPAX module had such sophisticated capabilities back in 1987. The more I learn about it, the more impressive it is.

There are other examples: The Advantage Pac and the IR printer module also act on "special" OpCopes to switch their banks .... so it was not only the HEPAX. Also the ZEPROMS implemented their own bank-switching scheme... so imagine: the NUT CPU is happily NOPing while all that wild bank switching happens ;-)

If the HEPAX, Advantage and IR modules handled these special OpCodes in h/w, how are CL, V41, etc. able to reproduce that behavior, meaning how do you know exactly what to have the emulation layer do to emulate the module's h/w behavior?

Is it "simply" educated guessing (e.g. looking at disassembled code, then taking a stab), followed by lots of testing, then rinse and repeat until it works?