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HP Forum Archive 21

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15C LE bug: p124: momentarily display the imaginary part of the number
Message #1 Posted by Rich Messeder (US) on 5 Apr 2012, 8:20 a.m.

p124:"Hold the key down to maintain the display."

a) This is not a clear instruction: what key? This an aside comment because it could be made more clear the first time that it is referenced, as it is later in the manual.

b) DOES NOT WORK FOR ME I must release both the f and (i) keys, then the Im part displays briefly. It doesn't matter in what order I release the keys; the effect is the same both ways. DO I HAVE A DEFECTIVE UNIT, or is this simply a document error? It seems to be a firmware issue.

The original 15C works like this: Press f, then (i). Release the f key and hold the (i) key to maintain the display of the Im part.

I assume that the 15C LE is supposed to act exactly like the original 15C.

I don't know the firmware version. CNA21102WB.

      
Re: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #2 Posted by Alexander Oestert on 5 Apr 2012, 8:30 a.m.,
in response to message #1 by Rich Messeder (US)

On both my LE units it works exactly like on my original.

      
Re: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #3 Posted by Luiz C. Vieira (Brazil) on 5 Apr 2012, 9:05 a.m.,
in response to message #1 by Rich Messeder (US)

HI.

Please, allow me to ask you a question.

Quote:
Press f, then (i). Release the f key and hold the (i) key to maintain the display of the Im part.
The [f] key is a prefix key, so it must be pressed prior to the function key itself. I am not sure if I misunderstood, but if you keep the [f] key pressed while pressing the [(i)] key, chances are it will not work as expected in the HP15 LE. In fact, I do not recall learning about any HP calculator before the HP28/HP18 that had a prefix key pressed while pressing a function key. For example, the contrast adjustment with [shift-key]/[+] or [shift-key]/[-] was available only when the HP28/HP18 were released.

I am not taking into account the Voyager self tests and radix mark selection, because in this case the operations are performed at the moment the calculator is turned on, and the [ON] key is not a prefix key. Also, contrast adjustment is not a regular Voyager characteristic, it came only with the HP12C Platinum.

Cheers..

Luiz (Brazil)

Edited: 5 Apr 2012, 9:06 a.m.

            
Re: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #4 Posted by Rich Messeder (US) on 5 Apr 2012, 9:33 a.m.,
in response to message #3 by Luiz C. Vieira (Brazil)

Well, Luiz, Thanks so much for that post!

It seems that I have been using an odd keystroke combo on my original 15C that works this way: Press and hold f. Press and hold (i). Release f. View complex part of number. Release (i).

/That/ is what I tried on the 15C LE. When I changed the steps to this: Press and release f. Press and hold (i). View complex part of number. Release (i).

It works...so, no bug! Now I must undo years of reflex ;-) I tried the "new" way on my original 15C, and it works that way, too. (IT works both ways; the LE only works one way.) Now, I don't usually press and hold the f key for any other operations that I can think of, so why do I have /this/ habit? Dunno, but it always worked, so there was no reason to change. Maybe it is because I misunderstood the original manual (p 124) when I first encountered it. Later in the manual, the f (i) combo is referenced in programs (see p133, for example), but by that time I had the "wrong" combo in mind, and never changed it. Clearly the f key is meant to be released before pressing (i).

Thanks so much for taking the time to comment. It seems that even this old dog can be taught a new (old) trick! ~R~

                  
Edited: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #5 Posted by Luiz C. Vieira (Brazil) on 5 Apr 2012, 9:42 a.m.,
in response to message #4 by Rich Messeder (US)

HI.

Good to know it worked the expected way. 8^) Being an old dog myself (50 Y.O.) I totally know what you mean.

(added) About the [f][(i)] sequence in programs. Please, notice that the [f][(i)] sequence is not programmable (p. 80, bottom). The example in page 133 (both new and vintage manuals, actually) refers to the use of [f][(i)] to show imaginary part of a complex number in the X-register without disturbing stack contents.

Cheers.

Luiz (Brazil)

Edited: 5 Apr 2012, 9:59 a.m.

                        
Re: Edited: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #6 Posted by Paulo MO on 5 Apr 2012, 5:16 p.m.,
in response to message #5 by Luiz C. Vieira (Brazil)

Hey, Luiz. How come 50 Y.O. implies one's an old dog? Oh, I see! You're speaking hexadecimal, right? ;-)

Cheers Paulo (0x32)

                              
Ouch! Busted...
Message #7 Posted by Luiz C. Vieira (Brazil) on 5 Apr 2012, 5:33 p.m.,
in response to message #6 by Paulo MO

n.t.

                  
Re: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #8 Posted by Bart (UK) on 5 Apr 2012, 9:52 a.m.,
in response to message #4 by Rich Messeder (US)

I have always assumed that when the manual shows consecutive key symbols, it means release in between unless specified otherwise (e.g. the 50g getting to graph menus when in RPN mode). The DM-15CC works the same way as the 15C-LE. I guess the original 15C was being kind to you ;-)

      
Re: 15C LE bug: p124: momentarily display the imaginary part of the number
Message #9 Posted by Bart (UK) on 5 Apr 2012, 9:48 a.m.,
in response to message #1 by Rich Messeder (US)

Quote:
p124:"Hold the key down to maintain the display."

a) This is not a clear instruction: what key? This an aside comment because it could be made more clear the first time that it is referenced, as it is later in the manual.


Mentioned earlier in the manual: p.122, last line of the example: "Displays imaginary part of sum while the (i) key is held."


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