RPN   Windows Desktop Calculator
. explanations
RPN Reverse Polish Notation, postfix notation 
As opposed to the Adam - Riese notation with * / precedence over + - and the use of 
parentheses, the RPN only uses COMMANDS. 
It is also well known as the STACK OPERATING notation and the ENTER notation, 
as introduced 30 years ago by Hewlett Packard with the HP-35 handheld calculator. 
IS EASY! Using RPN is surprisingly easy, there are virtually no rules to learn, except one: 
     the order of actions (commands) is the only important issue.
The calculator is ideal for engineers and scientists for small online calculations. The 
program is so small and does not waste resources, so that you can leave it on the 
Windows desktop all the day. While calculating you get all intermediate results 
visible on the stack, so you can prove the validity of your "algorithm" on the fly. 
All commands can be entered with the mouse, most with the keyboard too. It will 
need a few minutes of training only to use the RPN calculator economically.
COMMANDS Saying that RPN uses COMMANDS means that there is no distinction between 
operators and operands, because there are no operators and no operands. Even the 
number entry can be treated as a command: put nnn on the stack! 
+ and - and * and / are no operators in RPN, they are commands. The user should 
treat them as mnemonics only for the commands "add!", "subtract!", "multiply!", "divide!". 
There are several housekeeping commands to manipulate the cells on the stack, 
DUP and SWAP, OVER and DROP etc. 
You should treat the stack as a stack of small paper sheets, containing one number 
each and lying on the desktop. One cell is the top cell, the TOS (top of stack), next is 
It is typical for the RPN that variables are unnamed (as opposed to usual programming 
practices), they are solely referred to by their position on the stack.
Adam Riese RPN
20*log(213.5 / 116) 20 enter 213.5 enter 116 / log * 
or    213.5 enter 116 / log 20 *
(5-7)/(16+2) 5 enter 7 - 16 enter 2 + /
You see that the Enter button (Return on the kbd) is used to put a number on the TOS, 
but in many cases it is not necessary to press Enter, it is automatically performed by 
the following command, it is built-in in the command.
SCREENSHOT RPN screenshot, nat. size
DUP F2 make a copy of TOS and put it on top of the stack
SWAP F3 exchange NOS with TOS
OVER F4 similar to DUP, but copy NOS
PICK F5 select one stack cell with the mouse and copy to TOS
ROT F6 rotate the whole stack by one location
DROP F7 delete the TOS, NOS -> TOS
Usually all commands operate with TOS and, if applicable with NOS. 
The ! command can also store the value of the selected (mouse) stack cell to a 
register, and ^Ins works on the selected cell too. If no cell is selected, TOS is 
REGISTER The register is a small array to store 10 numbers for later use. Usually the values 
to calculate with are on the stack, it is deep enough and you have commands to 
copy any stack location to TOS. 
! store TOS to the selected register
+! add TOS to the selected register
@ copy the contents of the selected register to TOS
The register's contents and the stack are saved to RPN.INI, so that you can 
continue your work next morning. 
Some users will notice that the mnemonics are derived from the FORTH 
programming language.
Clr clear the number entry panel
ZwA ^Einfg copy TOS to clipboard, ^Ins. (textstring)
E exponent, for 1.02345E-6 floating entry
<- back-step at number entry
- change sign, negative number entry. Kbd: _ underline
lx last X, copy the last entered number to TOS
x^y TOS ^ NOS
1/x  and  -x reciproke and negate TOS, convenience commands
arc, deg convert TOS degrees to 180° = pi and reverse
° / pi switch for trigonometric functions
->R  and ->P To Rectangular, To Polar. Complex number utility
F1 Hilfe RPN.HLP, German. Win 3.x style help. 
You will not need it, all is explained here.

free download
   The program runs on Win 3.x, Win95 and WinNT
It would be nice: office@meg-glaser.biz
   This page is made for those users of the RPN calculator, who cannot read the German F1-help.
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