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TVM WP34s trouble - Printable Version

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TVM WP34s trouble - Jim P - 06-28-2013

I will fully admit to being an idiot... if I'm missing something obvious. Otherwise it's a simple struggle with the TVM routine (the enhanced one that is with the ver 3.2 build.) The text file accompanying the routine didn't give me the clues I was looking for. I entered a value, then A followed by A for N, and a new value, then A followed by B for I, and so forth, skipping D because I wanted to solve for "PMT" -- But then -- everything I tried (followed by D to solve for PMT) gave me ridiculous answers or square roots, which doesn't seem helpful.

Apologies to Franz who wrote the routine if my blindness indicates simple low IQ.... might I suggest a couple of "examples for dummies" in the text file along with keystrokes? It's the only thing keeping me from using the WP34s as my regular machine.

Re: TVM WP34s trouble - Marcus von Cube, Germany - 06-28-2013

If D gives you a square root instead of running the TVM application there must be something wrong with the current program counter. Make sure you start 'TVM' correctly from CAT or with XEQ'TVM'.

I'm not proficient with Franz' code so we need to wait for an answer by him.

Re: TVM WP34s trouble - fhub - 06-28-2013

Hi Jim,

the only thing I could imagine is that you didn't press the (prefix) key [A] before [D].

Maybe you thought that [A] as prefix is only needed for entering a value and not for calculating, but the prefix [A] is needed for both, entering and calculating any of the five TVM values.

Assuming you've started the TVM solver with XEQ'TVM' (or selecting it from the CATalog and press XEQ), here's an example of a calculation for PMT:

   10 [A][A]      enters N  and displays N=10
5 [A][B] enters I and displays I=5
1000 [A][C] enters PV and displays PV=1000
-2000 [A][->] enters FV and displays FV=-2000
[A][D] calculates PMT and displays PMT=29.50457...

In fact [A] is always necessary as prefix before any of the 5 TVM keys [A]...[->], and it just displays 'N I PV PMT FV' for about 10 seconds (waiting for your next keypress). Whether you _enter_ or _calculate_ any value depends on if you previously have entered any number: if you've entered a number it is just stored, but if you did not enter a number before, then this value is calculated.


Re: TVM WP34s trouble - Jim P - 06-28-2013

Thank you Franz,
I was not aware that one had to press A first no matter what. I'd been fighting this one for weeks and couldn't figure it out. This clears it up. Much appreciated and thank you for the routine!

Re: TVM WP34s trouble - fhub - 06-28-2013

I was not aware that one had to press A first no matter what.

Yes, this [A] prefix is not as easy as it _could_ be, but since we don't have 5 hotkeys on the WP34s (the 5th key [->] has a special function), using [A] as a prefix was unfortunately the only possibility I saw to use the 5 top-keys in a row.

I would also have preferred 5 (or even all 6) top-keys as function keys, but the WP34s team didn't fulfill this wish.

So let's wait for the WP43s ... ;-)