HP-15C: Fixing the CHS and Stack Lift Bug

[brouhaha]

(01-14-2023 09:01 AM)J-F Garnier Wrote:  Eric, is the fact you accessed this thread an indication that you are considering fixing this "bug"?

I hadn't really intended to fix any bugs. My primary intent was to accurately simulate the calculator as HP sold it.

Quote:GSB I with I<0 doesn't jump correctly

I wasn't aware of that one.

Quote:If a program ends with a conditional test that is evaluated false,
program pointer skips to line 1 and continue from there, instead of stopping at line 0.

I discovered that my self just a few days ago. I was researching how certain 15C user instructions are dispatched in the code, by putting just a single user instruction into a program then tracing from either SST or R/S. When I started looking into TEST, I discovered the bug.