Welcome to RpnCalc Financial

New: Trouble downloading? See the FAQ

A full-function programmable financial calculator for your Android phone.

Note: install the OI File Manager to enable the file picker which will let you load and save programs.

• Introduction
• Availability
• What's New
• User Manual
• Frequently asked questions — look here first before asking for help.
• Differences between RpnCalc Financial and an HP12
• See See user reviews and more at Cyrket.com

Introduction

RpnCalc Financial is a financial, math, and scientific RPN calculator. It contains a rich feature set for a wide variety of needs.

This is an RPN calculator. If you don't know what that means, or are not a fan of RPN, this may not be the calculator for you. If you are a business professional and you were trained on an RPN financial calculator, then this is the Android calculator for you.

If you're not sure, we recommend the free RpnCalc application, which will give you the chance to explore and decide if this is the interface for you.

Available on the Android Market.

Follow this link on your Android phone to visit the Android Market and download the application, or point your barcode reader to the code on the right.

RpnCalc Financial will be available soon on the Archos market. Watch our twitter feed or this spot for news.

News and updates available by following @RpnCalc on Twitter.

What's New

Version 1.25 introduces several new display features. These appear as new shifted functions on the right column of keys in landscape mode.

• Reg — display all registers
• Amort — display amortization table
• NPV — display NPV table
• Prog — display program memory

Using RpnCalc Financial

Quick Overview

In general, enter numbers using digits, ., EEX, and CHS, (for change sign). Use ENTER to enter the values. See Keyboard Shortcuts, below for keyboard shortcuts.

Use the f and g buttons for shifted functions.

The calculator uses a 16-level stack (see stack size, below). The top four levels are labeled X,Y,Z,T and are shown on the display.

There are 20 memory registers, plus some registers used for financial calculations. The STO and RCL buttons can access the memory registers. The ∑ buttons write to the statistics registers and RCL + ∑ buttons let you recall them directly.

The menu key allows you to switch calculator modes. This can be done any time and does not interrupt any in-progress calculation. Want to compute compound interest on e^sin(30)% interest rate? Just start in scientific mode and switch to financial mode.

Contents:

• Introduction to RPN
• Calculator functions
• General
• Financial
• Scientific
• Programming
• Menus
• Copy and Paste
• Keyboard Shortcuts
• More on stack operations
• Hex Mode
• Programming
• Developer's Notes

• Reverse Polish notation at Wikipedia
• RPN at the HP Museum
• Reverse Polish Notation at calculator.org

How RPN works

In a nutshell, Reverse Polish Notation means that calculator functions are performed as soon as you command them. With RPN, you enter two numbers, press +, and the numbers are added immediately.

In contrast, an algebraic calculator remembers that you pressed + and executes it later. For example, if you were to enter "1 + 2 × 3 =" into an algebraic calculator, the addition would not occur until the very end.

Because of RPN's "do what I say" approach, the "=" key and parenthesis keys would be superfluous. RPN calculators do have an "Enter" key, on the other hand, to separate one numeric entry from another.

As a practical example, let's look at the "1 + 2 × 3" example from above. Instead of entering the expression as it's written, we calculate it the way we would actually solve the problem with pencil and paper. That is, first we would multiply 2 and 3, then we would add 1.

On an RPN calculator, the process would be to first enter the value 2 with the key sequence 2 ENTER. Next, we would multiply by 3 with the sequence 3 ×. Finally, we would add 1 with the sequence 1 +.

This may all seem a little confusing to someone who is used to the algebraic style of keyboard input, but after a little use, you will come to find RPN to be a more intuitive interface.

In short, RPN works the way your brain actually works, not how you write things down on paper.

A point to ponder: algebraic calculators actually use a mixture of algebraic notation and RPN. For two-number functions, like addition, an algebraic calculator uses algebraic notation, while for one-number functions like square-root or 1/x, you find yourself using RPN. For example, an algebraic calculator computes square roots by first having you enter the number, and then pressing the √ key.

How would you compute √(4²+3²) on an algebraic calculator? Damned if I know, and I bet you don't know either. Maybe it's in the manual. Either way, I guarantee it's really a mixture of algebraic and RPN.

The stack

The stack is a storage area within the calculator that holds values until they can be processed. Both algebraic and RPN calculators have stacks, but RPN calculators expose the stack to the user.

The stack in RpnCalc and RpnCalc Financial holds sixteen numbers. The most recent four numbers are shown on the display and known as X, Y, Z, and T, with X being the most recent.

Try it: Key in a number and then press the ENTER key. See that the number you entered as X has been copied to Y. When you enter another number, it becomes the new X value. Press ENTER again. Now you'll see that Y has been moved to Z and X has been copied to Y as before.

Key in yet another number and press ENTER again. Now, the old Z value has been moved to T, Y has been moved to Z, and X has been copied to Y.

The display might now look like:

T: 123.00
Z: 456.00
Y: 789.00
789.00

If you keep entering numbers in this way, the stack will fill up with data, with the most recent data always in the X display. This process is known as "pushing" the stack, since each new value pushes the previous values deeper into the stack.

You can review the contents of the stack by pressing the R↓ key. After you've pressed this key sixteen times, the stack will be back to where it was.

Two-number functions, such as + take the most recent two numbers (X and Y) from the stack, perform the operation on them, and place the results back onto the stack as X.

Because two values were replaced by one value, the stack is then "popped", with older values making their way back to the front of the stack.

Try it: we'll re-visit the "1 + 2 × 3" problem, but this time enter the numbers in the order they appear. Since adding 1 to 2x3 is the last thing to happen, the value 1 will sit in the stack until the end.

Another example

Let's evaluate:

    3+7²
    ————
    8+5

On paper, you would first find the value 7², then for 3+7², then the value for 8+5, and then divide them. With RPN, we do the exact same thing.

(Note: we use the menu to switch to scientific or basic mode — there's no x² key in financial mode.)

You enter	The display shows	Notes
MENU		Switch to scientific mode
3 ENTER	T: 0.00 Z: 0.00 Y: 3.00 3.00	First value entered
7	T: 0.00 Z: 0.00 Y: 3.00 7	X = 7
f X²	T: 0.00 Z: 0.00 Y: 3.00 49.00	X receives 7²
+	T: 0.00 Z: 0.00 Y: 0.00 52.00	X and Y are added
8 ENTER	T: 0.00 Z: 52.00 Y: 8.00 8.00	8 entered, previous value pushed into stack.
5 +	T: 0.00 Z: 0.00 Y: 52.00 13.00	X receives 8+5
÷	T: 0.00 Z: 0.00 Y: 0.00 4.00	And finally, we divide.

One last stack trick

Watch carefully what happens you press the enter key. The stack gets pushed, but now there's two copies of the X value on the stack.

T: 123.00
Z: 456.00
Y: 789.00
789.00

If you enter another number, the X value gets replaced with the new number. But if you want, you can just go ahead and use the duplicate copy in the stack.

Let's compute 3 + 7² without using the x² button.

Finally, let's compute 5³:

• General
• Financial
• Scientific

General Calculator Functions

• Percentages
• Statistics

There are more statistics functions in the Financial calculator mode, below.

Financial Calculator Mode

Use the menu to switch to financial calculator mode.

• Date Calculations
• Interest Calculations
• Net Present Value
• Bond Pricing
• Depreciation
• Statistics
• Some useful links

Sign convention

Money that goes out is represented as negative numbers. Money that comes in is represented by positive numbers.

For example, if you deposit money in the bank, you would enter the initial deposit as a negative number since this is money leaving your pocket to go to the bank. When you withdraw the money later, the number is a positive number since it's money coming back to you.

If you borrow money and then pay it back in installments, the initial loan ("present value") would be a positive number since it's money coming to you. Your monthly payments would be negative numbers since they're money going out.

Negative Numbers

In the examples below, negative numbers are frequently given. These are entered using the CHS key, not the - key (which indicates subtraction.)

Example: A $10,000 expenditure is entered as 10000 CHS. In these notes, we will write it as -10000.

Functions:

Odd Periods

It's possible that a calculation will involve a fraction of a payment period. For instance, you might open a bank account in the middle of the month at a bank which does its interest calculations at the end of the month. Your first month's interest won't be computed over a complete month.

When an odd period is in effect, the odd period may be calculated with compound or simple interest. The "C" flag selects compound interest, and can be set or cleared with the sequence STO EEX

Data entry vs computation

If you enter or compute a number, then press one of n, i, PV, PMT, or FV, then the value will be stored in the corresponding interest register.

If you enter an interest-related value, and then immediately press another interest-related button, that value will be computed instead. Try out some of the examples below, and it will become clear.

Interest Calculations
FIN	Clear all financial registers.
n	Enter the number of periods (e.g months) for the interest calculation.
12x	Multiply X by 12 and store as n. A useful shortcut when time was specified in years but interest is compounded monthly.
i	Enter the periodic interest rate in percent.
12÷	Divide X by 12 and store as interest rate. A useful shortcut when interest is specified as annual percentage but interest is compounded monthly.
PV	Enter the present value
PMT	Enter the periodic payment
FV	Enter the future value
BEG	Set "Begin" mode, indicating that payments occur at the beginning of the payment period.
END	Set "End" mode, indicating that payments occur at the end of the payment period. This is the default.
STO EEX	Set or clear the "C" flag, which indicates that compound interest will be used on odd periods (see above).
RCL	Followed by one of n, i, PV, PMT, or FV. This recalls the specified financial register.
RCL	Followed by 12× or 12÷. This recalls the specified financial register and divides or multiplies by 12, respectively.
FV	Compute future value from other four terms.
	Example: You start depositing $100 into a savings account at the start of every month. The account earns 6.25% interest, compounded monthly. How much will you have at the end of 10 years? Solution: Enter: FIN BEG (payments at the start of each month.) -100 PMT (negative because it's money going out.) 6.25 12÷ 10 12x (period = 10 years x 12 = 120 months) FV Answer: $16,698.71
PV	Compute present value from other four terms.
	Example: You open a savings account that pays 5% interest and deposit $50 at the end of every month afterwards. You want to get $5000 back at the end of four years (48 months). What initial deposit do you need? Solution: Enter: FIN 5 12÷ (Annual interest rate/12 = monthly interest rate.) -50 PMT (payment = -$50) 4 12x (period = 4 years x 12 = 48 months) 5000 FV (Receive $5000 at the end.) PV Answer: $1924.21 initial deposit.
i	Compute interest from other four terms.
	Example: You open a savings account with $1000 and deposit $50 at the end of every month afterwards. You want to get $5000 back at the end of four years (48 months). What interest rate do you need to earn? Solution: Enter: FIN (clear financial registers) -1000 PV (present value = -$1000; negative because it's money going out.) -50 PMT (payment = -$50) 4 12x (period = 4 years x 12 = 48 months) 5000 FV (Receive $5000 at the end.) i Answer: 1.204% interest per month. (Multiply by 12 or use RCL 12÷ to get 14.45% per year.)
PMT	Compute periodic payment from other four terms.
	Example: You borrow $100,000 at 8% interest, compounded monthly. What does the monthly payment need to be to be completely paid off after 30 years? Solution: Enter: FIN 100000 PV (present value = $100,000 received) 8 12÷ (Annual interest rate/12 = monthly interest rate.) 30 12x (period = 30 years x 12 = 360 months) PMT Answer: $733.76
n	Compute number of periods from other four terms.
	Example: You loan somebody $40,000 at 10% interest, compounded monthly. They pay you back $2000 per month. How many months will it take to pay you back? Solution: Enter: FIN -40000 PV (set PV = -40,000; negative because it's money going out) 10 12÷ (10% interest divided by 12 = monthly interest) 2000 PMT (set payment = 2000; positive because it's money coming in.) n Answer: 22 months. This value has been rounded up to the next whole number of periods. The final payment will be less than the others.
	Example: How much is the final payment? The way we solve this is find the future value after 21 months. Solution: Enter: 21 n (set periods to 21) FV Answer: $1,923.46.
nf	Compute exact number of periods from other four terms. This is identical to the n function except that it can return a fractional number of periods. (Note that the nf function is the shifted function above the CHS button in landscape mode, and the upper-left button in portrait mode.)
	Example: same loan as before, exactly how long until it's paid off? Solution: Enter: FIN -40000 PV (same values as above) 10 12÷ 2000 PMT nf Answer: 21.97 months.
INT	Compute simple interest. Treats i as the annual interest rate and n as the number of days. Returns the total interest on PV. Result is calculated using both 365-day years and 360-day years (30-day months). Returns i365 in Z, -PV in Y, and i360 in X.
	Example: You loan somebody $5,000 at 10% simple interest. How much interest do they owe after 60 days? Solution: Enter: FIN -5000 PV (set PV = -5,000; negative because it's money going out) 10 i 60 n INT Answer: X = $83.33 interest due based on 360-day interest, Y = $5000 principal due, Z = $82.19 interest due based on 365-day interest. To compute total due, just enter + (360-day) or R↓ + (365-day).
AMORT	Compute amortization from financial registers and number of payments to be amortized. Returns the amount applied toward interest in X, the amount applied toward principal in Y, the total number of payments in n, and the remaining balance in PV.
	Example: You borrow $100,000 at 8% interest, compounded monthly on a 30-year loan. Your monthly payment is $733.76. After five years (60 months), how much interest have you paid and how much principal have you paid? Solution: Enter: FIN 100000 PV 8 12÷ -733.76 PMT 60 AMORT Answer: $39,095.81 interest, $4929.79 principal.
	Example: How about after another 5 years? Solution: PV and n were updated after the last example, and interest and payment haven't changed, so just enter: 60 AMORT Answer: $36,680.91 interest, $7344.69 principal.
Amort	Compute and display a complete amortization table.

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See Ehow.com and moneyinstructor.com for a discussion on bond prices.

In short, bonds are issued with a "face value" which is what the issuer will pay the bond holder when the bond matures. In addition, the issuer will also pay out a fixed sum, called a coupon payment, on a regular basis (typically twice a year) to the bond holders.

Bonds are usually sold for either a higher value than face value (premium) or a lower value than face value (discount). Bonds also have a risk factor associated with them, which can affect their initial price.

The bond functions of this calculator assume a bond with a face value of $100. The annual coupon payment, in percent, is written to PMT. The desired overall yield, in percent, is written to i. The purchase price (per $100 face value) is written to PV. The bond purchase date is entered into Y, and the maturity date is entered into X.

RpnCalc can compute depreciation using the straight-line method (asset loses a fixed amount of value every year), the declining balance method (asset loses a percentage of its remaining value every year), and the sum-of-year-digit method (see Wikipedia article for an explanation.)

For all depreciation methods, you first enter the asset's new value into PV, the salvage value into FV, the number of years into n, and the year for which you want the depreciation into X. For the declining balance method, you also enter the declining balance factor (typically 200%) into i.

Financial mode provides a few more statistics functions beyond those provided by the basic calculator, above.

Some useful links:

• Tutorials at TvmCalcs.org

Scientific Calculator Functions

Display and Data Modes
Bin, Oct, Dec, Hex	Change base. See below for more information about hex mode.
Fix, Sci, Eng	Set fixed-point, scientific, or engineering notation. Choose a display mode and enter a single-digit precision, e.g. FIX 2
D/R/G	Switch between degrees, radians, and gradians
Scientific Math Functions
Mod	Compute Y mod X
√x	Compute square root of X
x²	Compute square of X
e^x	Compute e to X power
10^x	Compute 10 to X power
ln	Compute natural log of X
log	Compute log base 10 of X
y^x	Compute Y to power of X
1/x	Compute 1/X
SIN	Compute sine of X
COS	Compute cosine of X
TAN	Compute tangent of X
ASIN	Compute arcsine of X
ACOS	Compute arccosine of X
ATAN	Compute arctangent of X
INT	Return integer part of X
FRAC	Return fraction part of X
X!	Compute X factorial
Conversions
R→P	Rectangular to polar; convert X,Y to R,θ
P→R	Polar to rectangular; convert R,θ to X,Y
HMS→H	Hours.mmss to hours
	Example: How many hours is 2:20:33? Solution: Enter 2.2033 H→HMS Answer: 2.34 hours
H→HMS	Hours to hours.mmss
	Example: What is 1.8 hours in hours, minutes, seconds? Solution: Enter 1.8 HMS→H Answer: 1:48:00 Hint: Use SHOW to see all the digits.
D→RAD	Degrees to radians
RAD→D	Radians to degrees
Permutations
P(x,y)	Return number of permutations of X items from a population of Y
	Example: How many ways to draw three marbles from a sack of 8? Solution: Enter 3 ENTER 8 P(x,y) Answer: 336
C(x,y)	Return number of combinations of X items from a population of Y
	Example: Same as above, but the order doesn't matter. Solution: Enter 3 ENTER 8 C(x,y) Answer: 56
Boolean operations (binary, octal, or hex mode)
AND	Compute X & Y
OR	Compute X | Y
XOR	Compute X ^ Y
<<	Compute Y << X
>>	Compute Y >> X

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This is easiest to use when the stack depth is set to four instead of sixteen (see stacksize, below). Suppose you want to get a list of powers of two. What you would do is enter 2 ENTER ENTER ENTER to fill the stack with the value 2. Then, just start pressing the × over and over again. Because the T register is copied after each operation, the stack will remain full of 2's for as long as you want.

RpnCalc can be launched with the "org.openintents.action.CALCULATOR" intent. When the user exits the calculator, the final X value will be a double value in the extras "X" entry of the returned intent. The Y, and Z values will also be returned. See OpenIntents.org for full details.

This allows any application to launch a calculator for the user.

Frequently Asked Questions

• Q: I can't get this app to download.
• Q: I can't find RpnCalc Financial on the Android market.
• Q: I'm buying a new phone. Is there a way to download RpnCalc Financial to it without needing to pay again?
• Q: Why does it need permission to write to SD card?
• Q: "No file picker found, see manual" — what now?
• Q: Is RpnCalc Financial compatible with the HP12C?
• Q: How do I switch from financial mode to scientific (or basic) and back?
• Q: Where is the Clx button?
• Q: I press 'PMT' (or one of the other financial keys) and it doesn't compute the value.
• Q: Can you make it display commas between the digits?
• Q: Does it support programming?
• Q: I get different answers on the HP12.
• Q: Why are period calculations always a whole number like 22, instead of say 21.7743?
• Q: I purchased RpnCalc Financial, and then lost it after a [reboot/system crash/phone upgrade/insert disaster here]. What do I do now?
• Q: I want to change my android market account

Q: I can't get this app to download.
A: Several people have reported this problem. It's a known bug in the Android Market and affects many, if not all apps. It's not specific to RpnCalc.

A1: Many people who have trouble installing apps from the market have reported that if they log onto the Google "Talk" application, the problem goes away. It doesn't make any sense, but there you have it. Give this a try before reporting problems.

A2: It is reported that you can re-verify your credit card by clicking https://checkout.google.com/main?ccUpdated=true which will cause the market to re-verify your card and unblock the transaction.

A3: If reconnecting to Google "Talk" doesn't help, cancel the order (you'll get a refund) and try again. If too much time has passed to cancel the order, request a cancellation through Google Checkout and I'll cancel it for you.

A4: Another common problem is that your phone might be running a firmware version that the Android Market doesn't recognize. This typically happens after your vendor sends a system upgrade without coordinating with the Android Market. When this happens, most paid apps become unavailable on the market, and apps you've already purchased can no longer be downloaded. This problem usually resolves itself within two weeks as the vendor scrambles to get their new firmware version registered at the market.

A5: Did you "root" (jailbreak) your phone? If so, there's nothing to be done — the Android Market won't send paid apps to root'ed phones for security reasons. All you can do at this point is request a refund through Google Checkout.

For more on this subject, see Android help forum How to resolve Market Place stuck at "Authorizing Purchase"

If you still have a problem, contact me with a detailed description of the symptoms.

Q: I can't find RpnCalc Financial on the Android market.
A: There have been a few incidents where a carrier pushed out a system upgrade without coordinating with the Android Market first. This results in paid applications all disappearing from the device and the market. This last happened with the Samsung Epic 4G in Feb 2011. It is also suspected of happening again to the HTC Aria. These problems usually resolve themselves in a week or so.

The best explanation of this problem is found on the support thread "Missing Applications On Marketplace".

Known issues:

• Samsung Epic 4G (Feb 2011)
• Nexus S (Resolved, Jan 2011)
• Motorola XT701 (Nov, 2010)
• HTC Aria (Sep, 2010)
• Sony Ericsson (Jul, 2010)
• HTC Desire (Mar, 2010)
• HTC Eris (resolved Jan, 2010)

Q: I'm buying a new phone. Is there a way to download RpnCalc Financial to it without needing to pay again?
A: No problem. The Android Market remembers your purchases. Once you've downloaded RpnCalc Financial, you can always download it again for free, as long as you're still using the same gmail account you originally used when you bought it.

Q: Why does it need permission to write to SD card?
A: It's used by programming mode to save and restore your programs.

Q: "No file picker found, see manual" — what now?
A: Install the OI File Manager on your system. It's available for free on the market.

Q: Is RpnCalc Financial compatible with the HP12C?
A: Do you mean really, truly, stand-up-in-court compatible? No it's not. To truly be compatible, it would have to run the same microcode as a real HP12C, which it doesn't do. In addition, there are known differences in the numeric rounding algorithm and in the handling of bad input data.

If you anticipate that you'll ever be on the witness stand in a lawsuit while the opposing attorney asks you pointed questions about whether or not you used an approved calculator to compute whatever it is the lawsuit is about, then this is not the product for you. Your humble narrator has been on the wrong side of that witness stand, and believe me, it's no fun.

But if you need a day-to-day financial calculator that's always with you, that doesn't take up any extra space in your pocket, and has a user interface you'll find familiar, then this is the calculator app for you.

Q: How do I switch from financial mode to scientific (or basic) and back?
A: The device's menu key lets you switch between the calculator's various operating modes. It also lets you bring up the built-in help pages.

Q: Where is the Clx button?
A: Replaced by the ← button, which is better. The ← button deletes one character when you use it during data input, and acts like the old Clx button the rest of the time.

Q: I press 'PMT' (or one of the other financial keys) and it doesn't compute the value.
A: Upgrade to the latest release. Older releases required that you press the "Find" key first, but that feature was removed by popular request.

Q: Can you make it display commas between the digits?
A: It should be doing that already, but there seems to be a bug on the Motorola Droid device which we're looking into now. If you see this on anything other than a Droid, please write to us.

Q: Does it support programming?
A: It does as of version 1.8 See Programming with RpnCalc Financial.

Q: I get different answers on the HP12.
A: If it's only a penny, that's normal. RpnCalc uses a different rounding algorithm than the HP12 and sometimes that last digit can be different. In the cases we've examined, RpnCalc was more accurate. If it's more than a few cents, please write to us immediately so we can look into it.

A2: If your problem occurs doing interest calculations, double-check that the Begin/End mode is correct and that odd-period compounding is correct. Experience has shown that the vast number of unexpected results were caused by one of these two settings.

A3: I have two reports of wildly wrong results that make no sense at all. In both cases, uninstalling the application and reinstalling it fixed the problem. There's no logical explanation for this other than perhaps the initial install got corrupted somehow. At any rate, this may be worth a try.

Q: Why are period calculations always a whole number like 22, instead of say 21.7743?
A: This is standard practice. Financial institutions aren't interested in dealing with fractions of time periods ("Dear mortgage holder, please send your final payment in 0.7743 months instead of the usual 1 month." — it just wouldn't work.) Instead, the number of payment periods is always a whole number of months, but the final payment is less than the others. See the example above to see how it's done. However, if you want a fractional answer, use the nf button instead.

Q: I purchased RpnCalc Financial, and then lost it after a [reboot/system crash/phone upgrade/insert disaster here]. What do I do now?
A: No reason to worry; I get paid the same either way. Wait — maybe that's not the answer you were hoping for. OK, seriously, don't worry. The Android Market remembers your purchases. Once you've downloaded RpnCalc Financial, you can always download it again for free, as long as you're still using the same gmail account you originally used when you bought it. You can even move your apps from phone to phone if you upgrade your device.

Q: I want to change my android market account
A: I don't know any automated way to do this. For now, go ahead, change accounts, purchase another copy of RpnCalc Financial, and then contact me for a refund on your first copy.

Differences between RpnCalc Financial and an HP12

• Display — RpnCalc Financial displays the Y,Z, and T stack values in addition to the X value. This makes it easier to keep track of your calculations.
• Stack — RpnCalc Financial normally has a 16-level stack instead of a 4-level stack. (When programs are running, RpnCalc Financial reverts to a 4-level stack for compatibility purposes.) This behavior can be modified via preferences settings; see stack size, above.
• CLx — RpnCalc Financial has a "delete" key ← instead of a "CLx" key. During number entry, the ← key deletes the last digit entered instead of clearing the entire display. When not doing number entry, this key is the same as "CLx".
• nf — In addition to the n key, which computes a whole number of payment periods, there is also an nf key which will compute an exact number of payment periods, even if the last period is a fraction. See above for more details.
• Save and Restore — The RpnCalc Financial menu allows you to save current program memory as a file on sdcard and recall it later. This allows you to have a library of useful programs.
• Rounding — RpnCalc Financial uses a different rounding algorithm from the HP12. On occasion, you will see results that differ in the last digit. Most of the time, you can set the display precision to a higher value and you'll see that the difference was actually much less than a penny. In all the cases we've observed so far, RpnCalc Financial had the more accurate results.
• Program and Register Storage — RpnCalc Financial always has 20 registers and 100 program statements. You don't lose storage registers just because your program got larger.
• On/Off — RpnCalc Financial has no "On" key. It has been replaced with a clear key.
• Clear Reg — The f REG sequence may be programmed on RpnCalc Financial. HP12 does not allow this.
• Continuous memory reset — There is no continuous memory reset for RpnCalc Financial. Use AC and PRGM to achieve the same effect.
• Programming — Programs are stored and displayed symbolically with RpnCalc Financial rather than numerically. Thus, for instance, STO + 1 is displayed as "STO + 1". In addition, the program files are written to sd card under /org/efalk/RpnCalc/, and may be edited with any text editor.

This software comes without any warranty, implied or otherwise.

Questions and comments can be directed to Ed Falk, efalk (at) users.sourceforge.net.