42's bug?


Could you, please, try this?:
Give wrong arguments for function COMB(ie: 1.2 enter 3 COMB)
so you get "Invalid data".
Now, give good arguments (like 9 enter 7) What's happen?



This is a well documented bug; please have a look here

and here

Hope this helps,


Hi, Massimo;

as I was typewriting my post, you were a faster trigger!

Best regards...


You're welcome Luiz!

BTW: you beated me on the 32Sii vs 42S question ;) 1-1



... and J. F. Garnier (if I am not wrong) have already mentioned some experiences with it. Also, Graig Finset's HP42S database mentions something about it. I extracted part of the file: (may I, Craig?)


Bug/2 (as in 1/2 a bug): Clear REGS (do CLV "REGS") and execute \GS+.
RCL now recalls the contents of registers 00 through 120,930 (indirect
above 99). You convert a hexadecimal address to a register number by
dividing by 16 and adding a constant (183 on the reporter's system,
but may vary). Exit this mode by setting SIZE to any non-zero amount.
Interesting addresses:

1FFC2 to 1FFFF copyright notice
40300 to 40309 speed nybble, contrast nybble, clock

Do COMB or PERM with X > Y. You correctly get "INVALID DATA". Now do
X<>Y. Do COMB or PERM again. It should work. Instead, you get
INVALID message again. EXIT + \v/x does not clear this condition.
However, any arithmetic operation it! [reported by Rich Homard,
b645zjo@utarlg.uta.edu; posted to Comp.sys.handhelds on 29 Oct 1991]

John W. Loux adds: Some of the earlier HP42S calculators had this
problem. This problem was fixed at one point. However, in a later
HP42S update, the problem reappeared. It seems that a combination of
hardware and software caused the problem. When the hardware problem
was fixed, the software problem reappeared! As far as I know, there
are no plans to fix the "bug" on the basis of the simple workaround.
The problem resurfaced in late REV B calcs and all REV C --- somewhere
between #3011 and #3055 is my understanding.

Hope this helps.

Best regards.

Luiz C. Vieira - Brazil


Well, thanks to both of you: I'm newby with the 42...
Is the next behaviour documented too?
(CAUTION: possibly you lose the memory!)
a) ClearSigma
b) Choose the linSigma mode in the Stat menu.
c) Write a Nx2 matrix with stat data and press Sigma+
What is happenning now? Pess MEM in Catalog menu...


Looks like it is related to Bug/2 (see Craig Finseth's site at previous post)...

My compliments! You are a true bug smasher :-)


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