How to code a calculator in assembly

[netwrq]

Hello... I am in dire help here. I am having troubles figuring out how to code my calculator. The problems are inputing a number into the calculator and outputting the TOTAL SUM. If anyone can figure this out, I will greatly apreciate it.

Thanks
Yahia Hegazy

 

[adholioshake]

Try using the DOS service interrupts for input and output.
For example, for buffered input:

ax=0ah,ds:dx=seg:offset of buffer.
int 21h

For output:

ah=09,ds:dx=seg:offset of output string.
int 21h

The thing to worry about here is the conversion between the characters input to the numbers used in the registers. Conversion to BCD might be easier for output.