Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!ut-emx!ccwf.cc.utexas.edu
From: daveh@ccwf.cc.utexas.edu (Dave Huang)
Newsgroups: comp.sys.apple2
Subject: Re: FTA Modulae
Keywords: Animation
Message-ID: <47417@ut-emx.uucp>
Date: 18 Apr 91 18:15:41 GMT
References: <1991Apr18.040333.2738@cs.uow.edu.au> <109414@tut.cis.ohio-state.edu>
Sender: news@ut-emx.uucp
Reply-To: daveh@ccwf.cc.utexas.edu (Dave Huang)
Organization: The University of Texas at Austin
Lines: 36

In article <109414@tut.cis.ohio-state.edu> meekins@tortoise.cis.ohio-state.edu (timothy lee meekins) writes:
>What's needed is a fast way (ie. ONE instruction) which can copy a byte from
>one row to another. The one that comes to mind id PEA. What FTA then does is

Do you mean PEI??

>to map the direct page to the source scanline and map the stack to the
>right-hand side of the destination scanline. Then by executing the  following
>statements, and entire scanline will get scrolled up one scanline (or two or
>three if you map them differently).

How do you do that? I thought the DP and stack have to be in bank $00,
while the screen is in bank $E1 or $01 if you shadow...

>	pea   $BE
>	pea   $BC
>	pea   $BA
>	pea   $B8

If you do that, won't it just push $00BE, $00BC .... onto the screen?
That's why I was wondering if you mean PEI...

>--
>+---------------------------S-U-P-P-O-R-T-----------------------------------+
>|/ Tim Meekins                  <<>> Snail Mail:           <<>>  Apple II  \|
>|>   meekins@cis.ohio-state.edu <<>>   8372 Morris Rd.     <<>>  Forever!  <|
>|\   timm@pro-tcc.cts.com       <<>>   Hilliard, OH 43026  <<>>            /|

BTW, is the last line of your .sig missing? I seem to remember that
there was a line that said "SHAREWARE" (appropriatly spaced with "-"s,
of course :-)
-- 
David Huang                              |
Internet: daveh@ccwf.cc.utexas.edu       |    "How much is that hamster
UUCP: ..!ut-emx!ccwf.cc.utexas.edu!daveh |          in the window?"
America Online: DrWho29                  |