HP97 The journey begins

[brouhaha]

(10-10-2024 08:14 AM)teenix Wrote:  HP calculator code is a bit of a head scratcher.

As a fellow reverse-engineer of HP calculator microcode, I would say that you have made a very polite understatement.

:-)

I continue to be impressed with how much progress you have made!

One trick I've been using to understand some of the HP microcode better is to modify the code to run on a more abstract calculator processor, which is similar to those of HP, but lifts many restrictions, and in particular the various limitations on branch and subroutine calls of actual HP processors. I modify the HP firmware by juggling blocks to remove jumps made unnecessary, so that related code is collected together rather than scattered all over. However, doing this is so much work that I'm not completely certain that it was a worthwhile exercise.