Re: A86: Question on tile maps
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Re: A86: Question on tile maps
Yeah, you use port 0 to change where video ram is located at. That's how
grayscale is accomplished. Sure, flipping pages would be faster than
copying it, but then you have to write your routines (or write code to
self-modify all routines) to use the two different buffers every other
frame. If all you have is a single putsprite routine, then it might be
worth it (but then are you really going to be the speed?). You could just
modify the address in putsprite whenever you flip buffers. But otherwise,
it gets to be a big hassle to have to keep changing buffers every frame.
It is a good idea, but the reasons above are why I have never used it.
Though Clem's latest (and very awsome) grayscale libray does use that method
for double buffering. So it's not bad, it just depends how you look at
it...
----- Original Message -----
From: <KidFedX@aol.com>
To: <assembly-86@lists.ticalc.org>
Sent: Wednesday, January 27, 1999 3:41 PM
Subject: Re: A86: Question on tile maps
>
>Just to put my two cents in... can't you change the ram that the calc. uses
as
>the video ram. If you stored the sprite in one place as they would look on
>the screen; and then your map in an other; you could just flip the video
ram.
>I think it talks about doing that in the Assembly Studio help file. I
don't
>have time right now to hunt it down; I just remembered it, and now I"m
making
>you all aware of it. This would let it go faster right?
>--Joe
>
>