RPN calculator

In short, an RPN calculator operates using a stack, into which you push numbers for subsequent maths operations. This means you enter the numbers first, then you calculate.

Example: to calculate “3+4” using an RPN calculator, you enter the following:

3

Enter

4

+

The RPN calculator is virtually modeless, and you do not have to worry about how many nested levels of parentheses you have keyed in (you can't). The only mode (apart from the mathematical modes) is the Stack Lift: this is an on/off mode that tells the calculator whether or not the next number keyed in should overwrite the X register. Stack Lift is on at all times except when Enter or BackSpace was just pressed.

Standard maths functions that operate on one number only are called without pressing enter:

Example: to calculate “sin (3)” on the RPN calculator, press:

3

s (or click the Sin button)

See also: