How to Use rpCalc



If you know how to use an RPN calculator (like some Hewlett-Packard models), you know how to use rpCalc. It stores previous results in four registers (usually labeled X, Y, Z and T), and the numbers are entered before the operators.

Of course the buttons can be clicked or tapped, but, for desktop usage, the quickest way to enter numbers and the four basic operators is to use the keyboard. For the other keys, the name on the key can be typed (not case-sensitive). What has been typed shows in the box below the keys. The tab key may be used to automatically complete a partially typed command.

A few keys have unusual labels to allow them to be typed: "RCIP" is 1/X, "tn X" is 10^X, "R<" rolls the stack back (or down), "R>" rolls the stack forward (or up), "x<>y" is exchange, "CLR" clears the registers, and "<-" is backspace.

A few commands ("STO", "RCL" and "PLCS") prompt for a number from zero through nine. This number will be the memory register number or the number of decimal places for the display.


The "OPT" button brings up a menu. This History View shows recent calculations in algebraic format. The Memory View shows the contents of the ten memory registers. The Settings item brings up various options.

The Settings options include remembering the window size/position, display options (duplicates of dedicated key settings), the number of history entries to save, and a view scale ratio to enlarge the text in auxiliary views (useful for high-dpi screens.