CHECKSUM 366911.
     This program will make the Model 100 into a full-function RPN (Reverse Polish Notation) scientific calculator, designed to
closely emulate the functions and operation of an HP scientific calculator:
     > All available functions and the keycodes are visible on screen.
     > Uses numeric keypad layout of numbers and mathematics keys for fast "touch typing" data entry and manipulation (function
key settings are not changed).
     > 10 data storage registers.
     > Last-X register for easy error correction.
     > Contents of 4-register stack, last-X register, and 5 data storage registers visible on screen.
     > Summation function (with correction feature) for finding means and standard deviation of x,y data.
     > Full trigonometric functions in both degrees and radians modes.
     > Conversion from degrees to radians and vice versa.
     > Logarithmic functions.
     > Number of decimal places displayed is selectable from zero to six; last digit is rounded.
     > Factorials.
     There are four screens of data that appear on the right side of the screen.  You can scroll between them using the left 
and right cursor keys.  Three screens are for displaying the available functions and codes, and the fourth displays five data 
storage registers.  The stack (registers X, Y, Z, and T) can be rolled up or down with the up and down cursor keys.  The 
backspace key acts like the "left arrow" key on the newer HP calculators (to erase one digit at a time for number correction).
     Functions such as square root, etc., are executed by typing in the appropriate keycode of up to three letters.  CAPS LOCK 
must be down.  The function appears in the "FUNCTION:" line, and is executed immediately after the last letter of the code is 
entered.  Most codes have mnemonics that do not use letters that are a part of the numeric keypad; however, a few codes do 
require that the NUM key be released.
    There are 10 accessible storage registers: 0 through 9.  The machine will prompt for the register number after executing 
the store or recall function.  Registers 1 through 5 can be displayed by scrolling the display.  The remaining five registers 
are also used to store the summation function data that are used in the mean and standard deviation functions, as follows:
     R0: n
     R6: Sum of X
     R7: Sum of X^2
     R8: Sum of Y
     R9: Sum of Y^2
    These registers are cleared for new data entry with the "clear sum" function (CA).  If an error is made in data entry, the 
incorrect data can be reentered and subtracted from the sums with the "sum minus" function (+ key).
     The program will automatically display the number in scientific notation if necessary.  The program is not perfect (
without making the program even longer) in respect to display formatting of some numbers.  Occassionally, very large or very 
small numbers will not format properly and will run onto other parts of the display, especially numbers in the displayed 
storage registers.  However, the value of the number in memory is not affected and can safely be used in calculations.  The 
display can be "repaired" without terminating the program by executing the "fix" (FX) function.
     After downloading, be sure to make the changes in the program listing that are given in lines 1000-.  This program is 
intended for SIG members' use only and is not to be sold.  Questions and comments are welcome.
     Terry Morgan  [75735,1635]

     I also have a shortened version of this program (about 3.2K) that does not have many of the scientific functions (like the
trig functions and exponentials).  You can create this shorter version by MERGING the following numbered lines (everything 
after this paragraph to the end of this file) with RPNCAL.100.

10 'RPNCAL--SHORTER VERSION (3.2K) by Terry Morgan [75735,1635] 9/83 REVISED 6/84 Copyright (c) 1984 NOT FOR RESALE
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430 IFR2=4THENR2=1
435 ONR2GOSUB440,470,500:R=1:GOTO50
510 PRINT@178,"              clrS=CA";
515 PRINT@218,"              mean=MN";
520 PRINT@258,"              stdv=SD";:PRINT@298,SPACE$(21);:RETURN
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