HP Forum Archive 19

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20b - Observations Message #1 Posted by Thomas Radtke on 15 July 2009, 9:04 a.m. It appears, the 20b acts partially like a RPL calculator: 1 ENTER 2 ENTER + results in 3 instead of 4. OTOH, a percentage operation a b % leaves a on the stack, as opposed to RPL calculators like the 48 series. Quite confusing, but I like it. An interesting bug: Some error conditions apparently leave an invalid number on the stack. Try e.g.: CE TVM reset N I/YR PV (ignore errors) Now cycle through the stack, some entries are missing. These are maybe invalid numbers.

Re: 20b - Observations Message #2 Posted by Gene Wright on 15 July 2009, 10:50 a.m., in response to message #1 by Thomas Radtke Hi Thomas! 1) Yes, the 20b uses a "command line" approach as an input to the stack. Your addition example points out the effect quite well. Another result can be that if you have a stack full of 4 values and begin typing another number, if you press ON/CE, you still have all 4 values. On a "true RPN" machine, you would have lost the value in T. On the 20b, T is lost only if you do something with the value you are keying it. ON/CE is an "abort" button. 2) The % operation works as "RPN" does. So, a bit of a hybrid, probably because it reuses the RPL approach to inputs on the stack. 3) If you're referring to an apparently blank display, then yes, this is a non-normalized number aka error result. I know HP is aware of this. Of course, a blank display should never be returned to the user, so this is a bug. What ROM revision is on your 20b?

Re: 20b - Observations Message #3 Posted by Thomas Radtke on 15 July 2009, 11:28 a.m., in response to message #2 by Gene Wright Hi Gene, Quote: What ROM revision is on your 20b? How to find it out?

Re: 20b - Observations Message #4 Posted by Tim Wessman on 15 July 2009, 11:40 a.m., in response to message #3 by Thomas Radtke On-PMT opens the hidden menu. Scroll up and down and you will see it in there. Also, can you give the example that returns the blank screen so I can check it is fixed? Thanks. TW

Re: 20b - Observations Message #5 Posted by Thomas Radtke on 15 July 2009, 11:56 a.m., in response to message #4 by Tim Wessman Quote: On-PMT opens the hidden menu. Scroll up and down and you will see it in there. SW Version shows 8 01 2008 Quote: Also, can you give the example that returns the blank screen so I can check it is fixed? Thanks. As a more simple approach to get one blank entry, press CE N I/YR Arrow down (4 times)

Re: 20b - Observations Message #6 Posted by Walter B on 15 July 2009, 3:44 p.m., in response to message #4 by Tim Wessman FWIW, SW Version 6 17 2008 shows the same bug.

Re: 20b - Observations Message #7 Posted by Gene Wright on 15 July 2009, 3:53 p.m., in response to message #6 by Walter B Of course, since that is an earlier firmware, it means it had not been fixed by August of last year. :-) Hopefully, unlike some software companies, updated HP firmware does not break things that used to work!

Re: 20b - Observations Message #8 Posted by Walter B on 15 July 2009, 4:07 p.m., in response to message #7 by Gene Wright Quote: Hopefully, unlike some software companies, updated HP firmware does not break things that used to work! Hopefully, but not for sure ;) Quote: Of course, since that is an earlier firmware, it means it had not been fixed by August of last year. :-) Oh, that was M DD YYYY :( Sorry I didn't recognize that.

Re: 20b - Observations Message #9 Posted by Gene Wright on 15 July 2009, 5:56 p.m., in response to message #8 by Walter B Oops. Tough to know when the digits don't indicate where the day is located, isn't it?

Re: 20b - Observations Message #10 Posted by cyrille de Brébisson on 16 July 2009, 8:37 a.m., in response to message #1 by Thomas Radtke hello, it's not an 'invalid number', which would be a serious bug, it's a perfectly normalized NaN number... the problem is that the UI does not realy know how to handle NaNs... I am trying to remove all occurrences of such problems. regards, cyrille

Re: 20b - Observations Message #11 Posted by Thomas Radtke on 16 July 2009, 9:06 a.m., in response to message #10 by cyrille de Brébisson Great, allthough this bug doesn't seem to affect normal operation. May I be so cheeky to ask whether someone is debugging the 35s? :^)

Re: 20b - Observations Message #12 Posted by Marcus von Cube, Germany on 17 July 2009, 2:40 a.m., in response to message #11 by Thomas Radtke I guess, the 20b software is a one man show and we are lucky he is here on the forum. :)

Re: 20b - Observations Message #13 Posted by bill platt on 17 July 2009, 1:34 p.m., in response to message #12 by Marcus von Cube, Germany Yes, that is true. And of course never overestimate how man people are behind the curtain! (It is always amazing to realize how much one motivated and talented person can do). I lurk most of the time on these issues but find it interesting to follow them.

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