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Financial Calculations for the HP41: another enhanced version - Printable Version

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Financial Calculations for the HP41: another enhanced version - Luiz C. Vieira (Brazil) - 04-16-2012

Hi folks, mostly Cheyenne.

After reasoning about the valid changes and enhancements that might/could take place, I got to a ‘quasi’ final version of the Financial Calculations program for the HP41C/CV/CX. The backbone was taken from the HP41 Standard Applications (original Financial Calculations) plus some info from the HP41 Financial Decisions Pack, program MONEY. I decided that by adding the following functionality would make the program better:

LBL a – acts as [12×] when inputting ‘n’
LBL b – acts as [12÷] when inputting ‘i’
LBL c – toggles between BEGIN and END payment mode
LBL d – toggles between integer or fractional computed ‘n’ (*)
LBL e – clears financial registers
LBL’MNY’ – startup label

(*) to match the HP12C operation; either one is a valid input regardless selected computed mode

Flags #2 and #3 are used in this version. Flag #2 signalizes BEGIN (set) and END (clear) modes as it happens in MONEY from Financial Decisions Pack. Flag #3 is not used in MONEY, but it is used here to signalize integer (set) or fractional (clear) computed 'n'. A brief inspection in the calculator display reveals which modes are selected.

I tested the program and the additional features with all related examples in the HP12C manual and in both the Standard Applications and the Financial Decisions Pack. They worked fine. Anyway, I will test all possibilities later, with an HP12C and an HP41 running MONEY to compare results. So far, I welcome anyone who wishes to give it a try.

All possible restrictions and considerations applicable to the original Financial Calculations program apply to this one as well because nothing was changed in terms of calculations, I just added the features.

About the listings: please, forgive me for the scanned images from the TRACE-like listing taken with the HP82143A. I felt it would be safer (and faster) to print it directly form the calculator against changing the existing list. I promise to provide a better one later. The list has been broken into first and second parts.

Please, have you found any discrepancy or any potential error, let me know. I’ll correct it as fast as I can. And if you believe it has applicability, I'll prepare the related HTML to propose it to Dave so it can be amongst the others in the HP41 library.


Luiz (Brazil)

Edited: 16 Apr 2012, 9:33 a.m.