HP 20b: test-menu

[Thomas Klemm]

Recently I wanted to change the display mode on my HP 20b to show all digits but I did't remember how to do that.
I didn't find the answer in the small booklet that came with the calculator so I searched online where I finally found it in the training module

Operating modes, clearing options and error messages.

Why not in Interest rate conversions or Hyperbolic functions I wondered.

However I was happy to find what I was looking for and of course it suggests itself to use FIX = -1 for that in the Mode-menu
whereas you have to use the dot in the shift-shift-digit-shortcut, if you know what I mean.

The important thing is always: be consistent!

For a moment I remembered a recent post of John H Meyers on comp.sys.hp48 where he stated:

Quote:

---

In 48GX, the STAT DATA menu (...) contains a [\GSDAT] label.

The left and right shift keys cause that menu key

to generate STO\GS and RCL\GS commands, respectively

(best seen when editing in PRG mode).

This is similar to how STEQ and RCEQ commands are generated

by the [EQ] label in the SOLVE ROOT menu (menu 75 on "G" series).

A number of other menus generate useful complete structures

when shifted, e.g. the various labels in PRG BRANCH

(menu 23 in "G" series):

LS IF -> IF THEN END

RS IF -> IF THEN ELSE END

Try all the others and see!

---

Obviously there were times people at HP designed things very clever.

But the worst thing of the Mode-menu is pressing the [=] button until the number
of digits you want is displayed. The stack is cluttered with all the numbers you
went through and your worthy results are lost. You should have known better not
to use the [=] button!

However all this has nothing to do with the subject but that's how I found the
lines with the description on how to perform a MEMORY CLEAR:

Quote:

---

The "master clear" of the HP 20b is accomplished when the following sequence is executed:

• press and hold [ON/CE]
  
• press and hold [N]
  
• press [FV]
  

DO NOT DO THIS IF YOU WANT TO KEEP ANY INFORMATION THAT IS IN YOUR CALCULATOR.

---

I can assure you that you will not loose any memory. I tried it several times.
And then I tried [ON/CE] [N] [Amort] as I would do on most other HP-calculators and

All Reset

appears.

Then I tried the other button [PMT] next to it on the left since you knewer know, right?
And alas we enter a test-menu:

• Tst Screen
  
• Tst Keyboard
  
• Checksum
  
  • 213.213
    
• Tst Battery
  
  • Bat Lvl = 3.0
    
• SW Version
  
  • 6 24 2008 2
    
• (c) Copyright 2008 HP Dev. C., L.P.
  
  • 2,048.000
    
• TSys
  
  • On
    
  • Off
    

In the screen-test you can press any key and the anounciators and the display will be shown
which is always funny to do. So after a while playing with that I entered the keyboard-test
which was a big mistake: first you may think you have to press them in a specific order but
then you might try to produce an error and skip one and nothing happens and then you start
wondering which of the keys will bring you out of this menu and at the latest now you're
relieved somebody at Apple invented the paperclip-trick.

However if you skip keyboard-test and succed to exit the menu you will find that this is yet
another method to set FIX = 3 on this amazing machine.

No wonder the ratings in the

customer reviews are so bad.

Kind regards

Thomas

BTW: Any idea what this TSys-menu is for?

[Gene Wright]

Gene responded in a rather foul mood...

Thomas wrote: "Why not in Interest rate conversions or Hyperbolic functions I wondered."

Gene: Well, how much redundancy do you want? I guess the material in Operating Modes module could have been reproduced in every other module. And, who is to say that someone needed to change the number of decimal places in those modules you mention? One other thing on this point - the shortcut to set -1 as the FIX setting was mentioned in the Datafile review I prepared for the machine. The shortcut of shift shift was added very late. I didn't find out almost until the review was done. Should every module have instructions on how to turn the calculator OFF?

Regarding the keys, you'd have to ask someone at HP. I wish they clicked too. The small guide is what it is. Menus are a philosophical choice to not have large quantities of functions on the keyboard. "Most" buyers don't like cluttered keyboards - they don't seem to buy calculators that have them. I am not "most" buyers and neither is anyone else here. If the choice is to have a menu such as the MATH menu that has 4 probability distributions or to have none at all, what choice should be made? I'll take the menus.

Yes, there are trade-offs compared to the "key per function" 12c style machine. The 20b still beats the pants off the TI competition.

Thomas wrote: "BTW: Any idea what this TSys-menu is for?"

Gene: Yes.

[Thomas Klemm]

Hi Gene

Hope you're in a better mood again. It was not my intent to upset anybody here in this forum and if I did I would kindly ask to accept my apologies.

After all it was my fault. I should have looked in the User Manual first where I would have found the information I was looking for. However I faintly remembered it might be in one of the training modules so I was searching there first. But there are several documents and I didn't know exactly what to search for.

So in the end, the documentation concerning this issue is ok. Still I think it's missing in the printed booklet I have at home.

Quote:

---

If the choice is to have a menu such as the MATH menu that has 4 probability distributions or to have none at all, what choice should be made? I'll take the menus.

---

Most of all I prefer a calculator I can trust. What's the use of a logarithm in a menu when it doesn't give the correct answer? It's not that I have to rely on that in my daily life. But at least I start to mistrust the whole machine then.

Quote:

---

The 20b still beats the pants off the TI competition.

---

The only TI calculator I've ever bought was a TI-25. But that was quiet a few years back. So I can not really tell. Still I can compare the HP 20b to some other HP-calculators.

Kind regards

Thomas

[cyrille de Brébisson]

hello,

>I didn't find the answer in the small booklet that came with the calculator..

it is there in the first chapter, 'Basic feature' page 9 of the user manual.. you probably spiked toward more advanced features and missed that one...
the function is located in the Mode menu like in most of the other modern HP calculator like the 49 series.

>But the worst thing of the Mode-menu is pressing the [=] button until the number of digits you want is displayed. The stack is cluttered with all the numbers you went through and your worthy results are lost. You should have known better not to use the [=] button!

That might be something that I can fix, but no guaranties here I am running out of ROM space :-(

> [ memory clear]
Where did you see the documentation about ON+N+FV? we need to correct that...

> [test menu]
Well, the test menu is not designed for end users, so don't complain there :-) to exit the keyboard test, press ON+PMT again by the way. the FIX=3 is set in order to make sure that the checksum shows OK and the system was not designed for a menu to have an action executed at exit (ran out of memory space), so sorry about leaving that at 3... but as stated above, you don't have much needs to go to the test system menu. BTW, if you set test system to ON, it will drain your battery fast as it enables the auto test system and continuously runs the CPU at full speed listening to the RS232 port...

cyrille

[Didier Lachieze]

Quote:

---

> [ memory clear]
Where did you see the documentation about ON+N+FV? we need to correct that...

---

It's in the HP 20b Introduction to the Learning Modules page 3.

[Thomas Klemm]

Hi Cyrille

Thanks a lot for your clarifications.

May I ask you a few questions in relation to this issue:

• Is there a list of known/fixed bugs together with the release?
  
• What is the desired procedure for us to post a bug?
  
• And how should we report issues with the documentation?
  

Kind regards

Thomas

Edited: 1 Apr 2009, 6:38 p.m.

[cyrille de Brébisson]

hello,

Quote:

---

Is there a list of known/fixed bugs together with the release?

---

so far, the known 'bad/math' bugs that I can remember are
- the log bug (when |exponent| is >=10) which has been corrected (althrough I do not remember the new release date)
- the IUTPN bug for number 1e-14..0.13 and 1-previous interval
they are of course some other bugs, mostly UI or crashes, but these 2 ones are the only ones that will return a bad result..

What is the desired procedure for us to post a bug?
send em an email, or contact HP and it should get back to me

And how should we report issues with the documentation?
same as above.

cyrille