clearing the keyboard buffer

[kismetlafiete]

My classmate and I are working on a pong game for our final project in our assembly class this semster... it's completely finished, the one problem we have is getting the input. We use the 16h interrupt (ah = 0) to see if a key was pressed in order to move a paddle. The problem comes after that... we tried to call 16h (ah = 1) after checking and hoped it would just clear it for us since a key was pressed already, but it waits for the key to be pressed again(although it does clear it).
If we remove the call to 16h (ah = 1), it never stops reading that the key was pressed. So we basically need a way to do the following:

1) was a keypressed?
2) decide which one it was
3) take the appropriate action
4) clear the key state(without pausing the program) to avoid looping.

we can do it all except for #4, so any help?

 

[kismetlafiete]

If there is an edit button here I couldn't find it. Anyway, I wrote the values for ah above incorrectly... when ah = 1, the bios will not wait; when it is 0, it will wait for a key to be pressed.

 

[dkdude]

21h DOS function 0Ch can be used to flush the keyboard buffer -so I read anyway....

mov ah,0c
mov al,0
int 21h

Regards


Jakob

 

[kismetlafiete]

I couldnt get it to work with ah=0ch, but it did point me in the right direction to find that

mov ah,08h
int 21h

works like a charm. Thanks for your help!