HP-34C Emulator

[BShoring]

Last year I got an emulator for the HP-34C for iPhone and overall I love it. The solve, integrate, gamma and other functions all work flawlessly.

The one problem I find is that if I have more than 2 labels the app gets confused. The original HP-34C is supposed to have 12 addressable labels: 0-9 and A & B. If I write a program with only two labels it usually functions correctly. However if I add more labels, the GTO and GSB functions cannot locate them. Sometimes the app just freezes and other times a GTO will just land in the middle of a subroutine. I've talked with the developer about this and he's very nice, and explained that he used microcode dumped from the physical machine, but that he has not given up looking for a solution.

I am wondering if 34C emulators for other platforms have this issue with the labels? Or did the original machine have this bug?

Love the app. Just wish there was a way to get a fix for this.

Bob

[Thomas Klemm]

Quote:

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I am wondering if 34C emulators for other platforms have this issue with the labels?

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With Nonpareil I can't reproduce that behavior. But maybe you can be more specific and post a small program that causes the trouble.

Kind regards

Thomas

[BShoring]

Hi Thomas,

Here's an example, taken from the HP-34C manual, page 112, which I post below. After keying in the program and rechecking the opcodes, I tried the examples at the bottom of the page and the calculator just launched into an endless loop.

Here it is:

LBL A, EEX, 4, X<>Y, X>Y, GTO B, 1 7 . 5, GTO 1, LBL B, 2 0,
LBL 1, %, RTN

Examples given in the book are:
15000 A should give a result of 3,000.00.

7500 A should give a result of 1,312.50.

Thanks for taking a look at this!
Regards,
Bob

Edited: 27 Mar 2013, 11:40 p.m.

[Thomas Klemm]

I can confirm the problem with this example. It appears to me that the GTO command has a bug: Sometimes it will just return to the first line but the next time it will just be ignored.

So if you run [GSB] [B] it will either end up in an endless loop or with 3.5 which is 20% of 17.5.

The following program works fine:

GTO B

17.5

GTO 1

LBL B

20

LBL 1

%

RTN

But when I add the command [x>y] beforehand and enter y = 10,000 and x = 7,500 so that the condition is not met the [GTO B] will be ignored but the [GTO 1] later as well!

I can hardly believe that this is a bug in the ROM of the HP-34C. Tons of people will have punched this program into their calculators. Maybe Eric Smith can have a look at that?

Cheers

Thomas

[Olivier De Smet]

Hi,

With go34c (android microcode emulator not based on non-pareil) the given program works nicely.

Either the rom of the emulator is corrupted or the cpu emulator still have some bugs in it.

Olivier

[BShoring]

Any plans to come out with an iOS version of go34c?

I'm currently using the iPhone/iPad app RPN-34C, which is otherwise great, except for the label search problem.

[BShoring]

So this problem is not limited to just one platform? Could be that the developer of my app and yours got their code from the same source. Hope we can get a fix so we can realize the full power of this great calculator.

[Mike T.]

Program seems to work as expected on a real HP34C - I ran it a dozen or so times and got the same result each time..

[BShoring]

Thanks so much Mike for trying it out on a physical HP-34C. So it appears that the label search problem is on some of the emulators, at least on Nonpareil and the iOS platforms. It is very frustrating as this is a very powerful calculator, but I can't have more than 2 labels in a program or the emulator gets confused.

Hope we can find a fix!

Thanks,
Bob
in San Francisco