The Museum of HP Calculators
HP Forum Archive 18
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|The HP 20b RPN Arcus Cosine Bug|
Message #1 Posted by Marcus von Cube, Germany on 17 Sept 2008, 8:19 a.m.
As I have already stated in the "First Impressions" thread, the HP 20b has a strange bug. I did some research and could narrow down the circumstances:
1) Select RPN mode
2) Select radian mode
3) Clear the stack (just to make things easier to check out)
4) Enter 1 +/-
5) Select Math/trig and scroll to COS-1
6) Press input
Now, the rounded value of PI is in the display and the argument -1 is in stacklevel Y. You can check it with swap ")" or roll down "(".
This is the only situation I could spot where the argument is not popped off the stack but pushed to Y. In degree mode, the bug is not present.
Edited: 17 Sept 2008, 8:22 a.m.
|Re: The HP 20b RPN Arcus Cosine Bug|
Message #2 Posted by cyrille de Brebisson on 17 Sept 2008, 9:21 a.m.,
in response to message #1 by Marcus von Cube, Germany
thanks, I will look at it.
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