Your most recent code doesn't work if you ever go into any of the screen's edges (A=1 or A=8 or B=1 or B=16) because even if you might not be trying to move in the offscreen direction, your code still ends up testing each space adjacent to you, of which one will be offscreen and cause an error.

It would be much easier to fix this up if we knew whether or not your maze would ever allow you onto those edges

EDIT: And there's my answer. So the problem is solved totally now?

Ah, I see.  I was working on making it go off the screen.

I always had massive trouble with detecting collision when going out of the screen. In the past, I would make my matrices 10x18 instead of 8x16 but that wastes a lot of RAM

I always had massive trouble with detecting collision when going out of the screen. In the past, I would make my matrices 10x18 instead of 8x16 but that wastes a lot of RAM

Thats exactly what i did for Shift Maybe it wastes a but of mem, but it sure makes the engine a hell of a lot faster I guess it depends on what kind of game your writing.  I had non tile-by-tile movement so I needed all the speed i could get

Basically you have a border around your entire map that is not displayed, but is there so that when you try to move off the screen, the collision routine has something to find (or else it goes wacky).  This can be avoided by clever coding, but often times the code needs to be very very clever to still be fast.

well you need to increase it on both sides

Heh i feel your pain, getting up at 5:00 every day for band is killing me X.x