HP-32E with errors ...

[teenix]

(04-28-2021 05:50 PM)ThomasF Wrote:  "0.5 Q-1" gives "0.0000" (ok)
and last example: "0.01 Q-1" gives after several seconds with a "running-program-blinking-display" "Error 0", but should be "-2.3263"

The Error 9 is an internal fault. It is a shame that there was not enough ROM space remaining to add code to display the faulty ROM or RAM, although for an end user it was probably of little use back then, but now it would be.

If it was the ACT I would expect many other faults. As you tested the RAM, it is probably a faulty ROM.

Another way to detect bad chips (not always) is that a faulty chip may be warm after being on for awhile.

The emulator at teenix.org has a ROM trace function. It will tell what ROMs executed for a given keypress when a break point has been set just before the key scan loop starts. Address ($06DB for the HP-32E)

Both of the listed [Q-1] functions execute from the same ROMs so it doesn't really prove which ROM could be in error.

It is time consuming to test code execution for the [Q] functions as many thousands of code lines execute.


Trace example: Q-1

ROM Chip Executions

ROM 0: Executed
ROM 1: Executed
ROM 2: Executed
ROM 3: Executed
ROM 4: Executed
ROM 5: Executed
ROM 6: Executed
ROM 7: Executed
ROM 8:
ROM 9:
ROM A:
ROM B: Executed
ROM C: Executed
ROM D: Executed
ROM E:
ROM F:


cheers

Tony