PalmCalc is an RPN scientific and financial calculator for the 3COM PalmPilot and Palm III family of PDA's. The calculator supports 25 scientific functions, 5 financial functions, 4 statistical functions, and has 20 memory registers (two banks of 10 each).
PalmCalc requires Palm OS 2.0 or higher, and 34K of RAM (88K including MathLib).
To install PalmCalc simply unzip the archive you downloaded and use the install tool (or equivalent) to install both PalmCalc.prc and MathLib.prc on your Palm Pilot or Palm III. You might also consider assigning the calculator button to bring up PalmCalc instead of the default calculator after syncing.
PalmCalc requires MathLib.prc to be installed on the Palm Pilot. If you already have MathLib installed on your Palm Pilot from some other program you don't need to install it again.
MathLib is not part of PalmCalc. MathLib is a free shared library that can be used by any OS 2.0 Pilot program that needs IEEE 754 double precision math functions. It's distributed under the terms of the GNU General Public License, and is freely available with full source code and documentation at the MathLib Information web page. It's not a part of PalmCalc, and you're not paying anything for its use; a copy is simply included in this archive for your convenience.
PalmCalc is based on Reverse Polish Notation (RPN). RPN differs from standard mathematical notation in that the numbers to be operated on are pushed onto a stack and then executed upon by a function. Hence the operation
12.5 + 7
is keyed as
The enter key is used to separate the two values. Most buttons on
PalmCalc can access three functions. The function or number on the
top of each button is accessed without shifts. The function just
above the button is accessed by pressing the f-shift key 
before pressing the button. The f-shift indicator will light in the
display when the f-shift is active. Similarly to access the functions
on the front of the buttons use the g-shift key 
.
The g-shift indicator will light in the display when the g-shift is
active.
Most functions remember the last x register value used during a
computation. This value can be accessed via the 
button.
PalmCalc has a 4 element stack. The elements of this stack are referred to by the names x,y,z, and t.
The value of the x register is what is displayed.
PalmCalc can display results in either fixed or scientific format.
Fixed format displays results with a fixed number of decimal digits
but will over- or underflow to scientific notation if the value is
too big or too small. Scientific format displays all results in
scientific notation with a fixed number of decimal digits. Press
and the number of digits to display (
through 
)
to set fixed format. Similarly press 
and then number of digits to display to set scientific format.
Numbers in scientific notation are displayed as
which is interpreted as the number 1.234567890 x 1099.
The 10 primary registers are accessed by pressing 
or 
and then the register number
through .
To access the secondary registers, swap the primary and secondary
registers with 
and then use
or .
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Numerals |
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Change sign of mantissa or exponent |
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Start entering exponent |
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Undo last character (or clear x register) |
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Minus |
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Plus |
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Times |
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Divide |
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Separate values and prepare x register to be overwritten |
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PalmCalc allows you to input numbers using Graffiti. The
characters 0 through 9, decimal, minus, sign and 'e' can be used
instead of the numeric buttons, ,
,
and 
.
PalmCalc has 20 registers -- 10 primary registers and 10 secondary
registers. Only the primary registers are accessible directly from
the keyboard. The secondary registers are used to store values used
for the financial and statistical functions. To access these
registers, swap the primary and secondary registers via
and then access the values now accessible via
and .
Use
to swap the registers back to their original configuration when done.
The secondary registers can be used to store your own values but you
must be careful not to use any financial or statistical functions if
you do so.
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Store into register n |
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Recall from register n |
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Swap primary and secondary banks of registers |
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Clear all registers |
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Swap x and y registers |
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Recall last x value |
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Clear x register |
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scroll up button |
Rotate stack contents up |
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scroll down button |
Rotate stack contents down |
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Set display to fixed format with n decimals displayed |
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Set display to scientific format with n decimals displayed |
The stack and registers can be viewed by choosing one of the Display menu items.
Choosing the Display-->Stack menu displays the four stack values as well as last-x:
Choose OK to return to PalmCalc or scroll (using the buttons on the PalmPilot or the arrows in the display) to see one of the other register views. The stack, primary, and secondary views are connected in a loop.
Choosing the Display-->Primary Registers menu displays the 10 primary registers. Similarly, choosing the Display-->Secondary Registers menu displays the 10 secondary registers.
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Displaying the secondary registers is an easy way to see the
values of the financial registers. Note that the interest (i) is
displayed as fractional interest and not in percent as it is when you
compute it using the 
button.
PalmCalc allows you to copy the values in the display for export to other applications like the Memo Pad. Simply choose Edit-->Copy from the Edit menu
to copy the currently displayed value onto the clipboard. The
value put on the clipboard honors the display mode (
vs. )
and the number of digits. Choose Edit-->Paste to push the current
value on the clipboard onto the stack. If the string on the clipboard
cannot be converted to a valid number, the PalmPilot will beep (when
system sounds are enabled) and the value of the x register will be
unaffected.
These functions operate on the value in the x register and replace it with the function result (f(x)).
The trigonomic functions are sensitive to the angle mode: degrees
or radians (
or 
in the display). When in degree mode, inputs to 
,
,
and 
are assumed to be in degrees and the results from 
,
,
and 
are in degrees. When in radian mode, the inputs and outputs are
assumed to be in radians (where 2*pi radians is the same as 360
degrees).
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f shift. Use to access functions above each button. |
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g shift. Use to access the functions at bottom of each button. |
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Absolute value |
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Sine |
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Cosine |
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Tangent |
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Arccosine |
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Arcsine |
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Arctangent |
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Value of pi |
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Set angle interpretation to degrees |
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Set angle interpretation to radians |
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Natural logarithm (base e) |
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Base 10 logarithm |
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Exponential function |
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Ten to the x power |
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Square |
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Square root |
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Reciprocal |
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Fractional part |
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Integer part |
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Factorial |
These functions use the values in both the x and y registers and place the result in the x register.
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Percent |
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Percent change |
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y to the x power |
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The financial functions are governed by the equation,
where s = -1 when PV is zero and s = 1 when PV is nonzero. When
the annuity mode (
mode) is 
(annuity due) then PMT in this equation is modified to be PMT*(1+i).
The financial functions have two modes: input mode and
calculation mode. PalmCalc is in input mode if a number
has been keyed into the calculator or any non-financial functions
have been executed. Executing one of the main financial functions
(
,
,
,
,
or 
)
stores the displayed value in the associated financial register.
PalmCalc is in calculation mode after any financial functions
have been execute and before any other functions that change the
stack are executed. The result of a financial computation is pushed
onto the stack:
Most of the time this should behave as you would expect. However, if for some reason PalmCalc stores a value when you intended to compute one, simply execute the financial function again to obtain the desired result.
Example: Suppose you are interested in determining the payment for a car loan of $18,500 at 7.25% interest for 5 years. The key strokes to solve this problem using PalmCalc are
to reset the financial registers (since the values in the
registers are maintained between sessions with PalmCalc it is a
good idea to reset the financial registers before each use of the
financial functions).
to set the number of periods (in months)
since the interest per month is 7.25/12 %
to set the principal or present value of the loan
to compute the payment per period (ans: $368.51)Example: What is the payment if you are willing to pay a balloon payment of $2,000 at the end of the loan?
Set the value $2,000 as the FV (balloon) for the loan.
to compute the payment per period (ans: $340.75)Example: How much interest do you end up paying with the balloon payment?
to compute the total payments minus the loan value
had to be pressed twice since the first time stored the total
payments into PMT.|
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Number of periods |
Input mode: Store displayed value as N. Calculation mode: Compute N. |
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Interest rate per period |
Input mode: Store displayed value as i (in percent). Calculation mode: Solve for i. If the solver doesn't converge an error '-e-' will be displayed. |
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Payment per period |
Input mode: Store displayed value as PMT. Calculation mode: Compute PMT. |
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Present value |
Input mode: Store displayed value as PV. Calculation mode: Compute PV. |
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Future value (or balloon) |
Input mode: Store displayed value as FV. Calculation mode: Compute FV. |
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Toggle between beginning of payment period |
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Clear financial registers and set payment period to the end (ordinary annuity). |
The statistical functions accumulate sums based on the values in
the x and y stack registers. These sums are used to compute the mean
and standard deviation 
or can be accessed directly via
and .
Use 
to reset all the statistical registers to zero before accumulating
sums. If you make a mistake keying in the x,y values and after
pressing 
,
rekey the errant values and press 
to remove them from the sums. The mean and standard deviation are
computed as
with similar equations holding for the y component as well.
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Accumulate x,y |
n is the number of sums accumulated so far. |
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Remove x,y |
n is the number of sums accumulated so far. |
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Mean |
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Standard deviation |
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Clear statistical registers |
PalmCalc makes no warranty whatsoever, either implied or expressed, as to the correct functioning of this software. When using this software, the user assumes all responsibility for any damages caused, directly or indirectly, by its use.
If you have questions, suggestions, bug reports, or you just want to tell us how you much you like PalmCalc you can contact us at PalmCalc@aol.com or on the web at http://members.aol.com/PalmCalc.
PalmCalc is available at PalmPilot Gear H.Q. (Phone: 817-461-3480, Fax: 817-461-3482). Also see the PalmCalc web site for up-to-date information about PalmCalc.
Last updated: 15-Jan-1999
(ordinary annuity)
