Assembly 8086: Check if a key is pressed to exit a program

Stev_o

Hi all.

This is one problem that has literally plagued me and i can't see to get a answer for it.

In my program i wish to do a simple loop function.

Draw a box that incerements and decrements up and down the screen.

However when a button is pressed i want the program to exit.

My problem is that i don't want the program to hang when i use INT21 Check Keyboard status as the loop won't continue the interrupt requires input to exit.

How do i get past this? I need to be constantly checking if their is input but do not wish my initial action loop to stop as a result of it.

Any help would be great.

dazberry

Check out Int 16h, AFAIR you can poll the keyboard state to see if a character is there...

mov ah,01
int 16h
jz ...

D.