Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!LOYVAX.BITNET!PGOETZ
From: PGOETZ@LOYVAX.BITNET
Newsgroups: comp.sys.apple
Subject: Page flipping
Message-ID: <8903141654.aa28044@SMOKE.BRL.MIL>
Date: 14 Mar 89 19:17:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 13


        Blink problems depend on the animation technique you use.  If you have
large figures (for ex, the walking man in Aztec which blinks), or if your
program does a "erase all figures, then plot all figures in their new position"
(large time gap), or if for some unknown reason you use Applesoft shape tables,
you get screen blink.
        Page flipping helps, but on the ][+ it can cause the undesirable split
effect when you flip while the raster beam is in the vertical middle of your
character.  Only on the ][e (and presumable ][c, ][gs) can you do page-
flipping right, since it provides you with information on when the electron
gun is doing a vertical blank (going back to start at the top again).

Phil Goetz