Calculator12

What is Calculator12?

Calculator12 is the re-imagining of the spirit of the HP12C financial/business calculator on the iPhone™ and iPod touch™. It is not a complete reincarnation, Bond calculations and programmability have been set aside in favor of allowing room for adding features to coming releases. It does however, do a solid job of emulating the calculator’s operation - you know how to use the original, you won’t have anything to relearn. If you are new to RPN, check out the tutorials (below, or Google works quite well), they’re really good and you’ll be glad you did because RPN saves keystrokes.

For more information about the HP12C and other fine calculation instruments, visit the The Museum of HP Calculators. it’s fun!

Are there instructions?

In a word, yes. Qualification: but not here. Rather than duplicate the superb efforts of others, you will find top flight on-line instruction and tutorials for the HP12C that are totally applicable to Calculator12 at the following websites:

Learning Reverse Polish Notation (RPN)

General introduction to the HP12C

Specific instructions for specialized real estate computations (you can buy the physical calculator here too)

Beyond the past.

Calculator12 takes advantage of the iPhone/iPod touch’s high resolution screen to add more information about the calculator’s state than was possible in the ‘80s. You will find the familiar “C” when it’s set to calculate compound interest, the indication as to whether a payment is due at the beginning or end of a period, and the designation of the date format (not abbreviated as was the case in the original). Calculator12 augments these by displaying the contents of each of the financial registers (no more wondering), and the last operation performed is shown to the far right just below the main numerical display. It even Yes, you can listen to music while using the calculator, and incoming phone calls, SMS and calendar alerts are presented to you in the normal fashion and are dealt with normally. You can start and stop Calculator12 anytime because it saves the stack and all data registers so the next time you start the calculator, it’s as if you never left it.

Who/what is Calculator12 intended for?

Well, first off, it’s for those who had an HP12C or have one now, and want that functionality built into something they already carry; their iPhone or iPod touch. Real estate professionals, financial planners, members of finance or accounting departments, bankers, folks shopping for mortgages or car loans will all find the time value of money (loan calculator) useful. The statistics package handles one or two variable statistics and is quite general in nature... not a specialized statistics calculator by any means, but one for the basics with uses in sales, inventory management and a host of other areas. Linear regression is used to estimate future or past values based on known or projected data (trending), but be advised that it does a lousy job with the lottery. The date calculation functions allow you to determine the number of days between two dates and to find the date and day of the week. You can find out what day it will be 234 days from now, how many days until you must have a present for that special someone, what day you were born on. Easy as pie. Calculator12 is also a very good tool for students, the original was approved for use during accounting examinations, and some courses only provided support for the HP12C.

Where can I buy?

On the App Store, of course! (click the App Store badge) Oh... Calculator12 will NOT work on a computer, it only works on the iPhone or iPod touch, you can get one of those from the kind folks at Apple, Inc.

If you wish to rave about Calculator12, by all means do so at Apple’s App Store! We love stars.

Known problems.

Normally, the last thing you see on a commercial website is a “problems” list but it is important that problems are disclosed as soon as they are known. Everyone who purchases the application will receive all updates for free -- but there is a quarantine process at Apple so updates are delayed by approximately a week.

8AUG2008 1555PDT: Devices with regional preferences set for “Switzerland” in French, German or Italian will display results with only the first digit after the decimal point being valid -- the entire result is still in the calculator and can be used normally but it shows the result by substituting the 2nd decimal place and beyond as zeros. There are more details on the forum including a workaround, the fix is in beta testing.

7AUG2008 0034PDT: FIX SUBMITTED 6AUG FOR REVIEW BY APPLE The interest calculation has another problem that I’m tracking down, the other functions are fine BUT it looks like negative FVs are giving me fits. At this point I don’t have a workaround.

6AUG2008 0815PDT: FIX SUBMITTED 6AUG FOR REVIEW BY APPLE Cannot calculate interest rate if PMT=0. This is a bug in my error checker, it’s slated for fix in v1.0.2 which I hope to upload 9AUG. There isn’t a workaround...

FIX SUBMITTED 6AUG FOR REVIEW BY APPLE If your regional preferences are set to “India”, the calculator will quit when you try to enter a negative number. The source of the problem is known, but to address it will remove its ability to provide comma separation into lakhs as is ideal. What will probably happen is that the next update will utilize more of a US norm for representing the numbers in spite of the regional preference, using a “period” as the radix separator and commas between large numbers.

WORKAROUND: you MUST set your device to a region other than India!!!