HP 41c STAT 1 module version 1A

[dmh]

Ok, I followed Diego's instructions below with the following results with the STAT 1A module.

CFFB 001
CFFC 031
CFFF 38C

I compared the code in the 1A and 1B module and there is no *c in the 1B module and the 1A code for *c is included in *a.

So any other reasons for the Service Module giving BAD ROM? Reading the manual it sounded like the version list was regularly updated so I'm wondering whether it gives an error as 1A is deprecated?

Once I save the ROM, what utility will decode them so I can look at them side by side and compare the FOCAL code?

(09-14-2021 12:58 AM)Diego Diaz Wrote:  Hi all,

Since you've said that the Service module shows the "BAD ROM" message and some functions don't work as expected. My advice would be to first check if the ROM revision of the module is "1A" or "1B" as it may be that the ROM has been damaged and shows "1A". (Although it is not frequent.)

The Service module does in fact calculate the checksum and compares it with the value at address xFFF.

Run HEXEDIT with just NoV-64d (HEPAX) into port 1 and your "STAT-1A" into port 3.

Enter ADR:CFFB, you'll see either "001" ("A") or "002" ("B")

SST should show "031" ("1")

Also if you SST until address CFFF you'll see the checksum ("2F1") in the case of the "1B" version.

It has also been confirmed that the function "*c" is called from "*a". Since this is a FOCAL module you can GOTO ALPHA *c and list this program to see if it has been included in the "*a" version of the "1B" counterpart.

Keep us posted!

Cheers.

Diego.