HP-41 Documentation, List of Bugs

HP-41 Documentation, List of Bugs

Postby mike-stgt » Sat Jun 19, 2021 11:42 pm

There may exist several lists of HP41 bugs here and there, alas I am not sure which of them is complete and/or primary reference. Quite probable following is known since long, for me it was new:

Jean-Francois showed me a quirk within 41CX in relation with 82143A and 82162A printer. I found, it is not restricted to the two printers. Now I see, already the 41CV is faultily.

Proof: Take an HP41CV (real or virtual, I used ROM version HFF with my toy), plug Advantage, PANAME and ZENROM (yes I know, to insert both same time is amoral, immoral(?) or unethical, but once for a test...) with ZENROM before (in a lower page than) PANAME, switch it on, enter in program mode the two commands XEQ ALPHA "CSRR" ALPHA and XEQ ALPHA "CSRUP" ALPHA (without quotes). Already at entry the lines are converted:
Code: Select all
 01 J+
 02 XROM "PLY"

Reason: The OS function GTRMAD (see VASM listing) scans pages 5..F for the ROM-ID in question, if found but with less functions than requested it continues scanning but then compares function number and ROM-IDs.
Note: To plug PANAME and ZENROM (both ROM-ID 5) just avoids the steps switch off/unplug PANAME/insert ZENROM/switch on/print program or enter program mode and BST or SST.
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Re: HP-41 Documentation, List of Bugs

Postby jeffcalc » Mon May 02, 2022 12:34 pm

The most comprehensive bug list seems to be the book "Extend Your HP-41" by W. Mier-Jedrzejowicz (available as pdf on this site), appendix C.
The quirk mentioned above is described (p.633).

As I was re-reading some French Micro-Revue journals, I found this undocumented nice little HP-41 bug (all versions), do:
DEG , FIX 2 , CF 24 , SF 25 , 9.99E99 , ENTER , R-P

See the bug ? Look carefully at the display.

Source: Micro-Revue n°8 , Sept_Oct. 1985, p. 72.

J-F
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Re: HP-41 Documentation, List of Bugs

Postby mike-stgt » Mon May 02, 2022 3:00 pm

Bonjour Jean-François !
jeffcalc wrote:The most comprehensive bug list seems to be the book "Extend Your HP-41" by W. Mier-Jedrzejowicz ...

That's remarkable. I guessed there might be a more recent list somewhere. Seems Włodek was pretty much up to date when publishing his "treatise".
... appendix C, p.633.
Speaking of it we should set the book in inverted commas.
... DEG , FIX 2 , CF 24 , SF 25 , 9.99E99 , ENTER , R-P

Comme toujours -- as always you tell me something new. Thank you.

Amicalement --
M.
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Re: HP-41 Documentation, List of Bugs

Postby rprosperi » Tue May 03, 2022 12:05 pm

jeffcalc wrote:As I was re-reading some French Micro-Revue journals, I found this undocumented nice little HP-41 bug (all versions), do:
DEG , FIX 2 , CF 24 , SF 25 , 9.99E99 , ENTER , R-P

See the bug ? Look carefully at the display.

Source: Micro-Revue n°8 , Sept_Oct. 1985, p. 72.

J-F


Interesting! As Mike says, completely new to me as well! Although certainly not early in the 41C's lifespan, and obviously published for all to see, it's quite amazing this discovery is not more widely known, especially since it is not merely a display bug, it actually changes 2 system settings!

Thanks for sharing this oddity. J-F! I'll send it to Wlodek and suggest a revision to the book is in order...
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Re: HP-41 Documentation, List of Bugs

Postby jeffcalc » Mon May 16, 2022 7:34 pm

jeffcalc wrote:As I was re-reading some French Micro-Revue journals, I found this undocumented nice little HP-41 bug (all versions), do:
DEG , FIX 2 , CF 24 , SF 25 , 9.99E99 , ENTER , R-P
Source: Micro-Revue n°8 , Sept_Oct. 1985, p. 72.


rprosperi wrote:Thanks for sharing this oddity. J-F! I'll send it to Wlodek and suggest a revision to the book is in order...


Correction: the bug is (somehow) documented in Wlodek's book, it is called bug #10. The description explains the effect of the bug with the MEAN and SDEV operations, but R-P has the same problem: it can generate an overflow if x^2+y^2 >= 1E100.

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