drd (07/18/82)
I have had 2 or 3 replys to my article requesting information on the
Apple's collision counter unfortunatly none of them could help me. One of
the replys suggested I get information from an Apple mailing list but I
don't know how to use one so please send me some information on the Apple
mailing list. Now after 2 or 3 hours of hacking I discovered the the Apple's
collision counter really does work if you are writing in Applesoft Basic and
using shape tables. The collision counter is stored at $EA on page zero of
the Apple's memory. When I figured out how it worked I was in progress of
writting a game and needed a quick way of checking for collision. The name
collision *counter* is a bit misleading it changes according to the graphics
data that was all ready there when the shape is placed on the screen if
some one can discover exactly why it stores the values it does I would like
to here from you. The only draw back of the collision counter is that
it won't work in machine language but compiling your Applesoft program can
fix that when you compiles with the TASC Compiler by Microsoft you get all
the features of Applesoft at machine language speed. Several games on the
market have been Basic programs compiled but they claim it was written
machine language one I know of is the game 'Human Fly' put out by CPU
Software. So with the information in this article and the TASC compiler
it is very possible to write those Hi-res games. I am just putting the
finishing touches on my original game and it has nice flicker free animation.
Gregg Stefancik
Morris Plains, NJ