Please can someone help me.
I need to design a program for a calculator to run on the 6502(emma board) there are 4 switches on the input which is in binary. Could please tell how to do it? If so could u tell me on how to do the addition, subtraction, muliplication and division separtly and how to put them togther to make the calculator.
I would be very gratefull if someone helped me.

Pardeep Chopra

The answer would fill a book. For starters, check out the source code repository at http://www.6502.org/source/source.htm . Look especially at "Floating Point Math" and "Integer Math". Calculators, more than other applications, normally need floating point which is more complex.