67 Emulator Available

[teenix]

(07-22-2016 04:59 AM)Alejandro Paz(Germany) Wrote:  I noticed on the HP-25 emulator that (some of) the opcodes seem to be encoded differently as in Nonpareil.
if s = 1
if s = 0

At position 1C1 it should read 25C and it reads 254, Any comments on why ? are there 2 different HW and ROM versions around ?

thanks !

Yes, that's true.

The "engine" that runs the emulator originally decoded the actual HP HEX code for each instruction. This approach was ok on the PC but proved instruction intensive when that was translated to PIC assembler to run all the calculators in the hardware project - that processor has a lot to do in a short time. Therefore new decoding was used and made the process much simpler and less time consuming.

However, to the best of my knowledge the instructions are all decoded properly as if they were executing in the real calculator hardware, even if you use the assembler to write your own code.

The HP HEX codes as displayed in the trace screen are matched to each individual instruction but since the HP67 and some other models were added, I haven't had time to match up the different codes that are used for these models. I am in the process of updating the symbol table but work and other commitments are using up my free time.

cheers

Tony