Newsgroups: comp.sys.amiga.datacomm
Path: utzoo!utgpu!news-server.csri.toronto.edu!torsqnt!lethe!compus!cccan!entity
From: entity@cccan.uucp (Cybernetworx)
Subject: Re: Jr-Comm
Message-ID: <1991Jun16.020152.2331@cccan.uucp>
Organization: CCCAN
References: <676276570.1@kcufgat.fidonet> <lord_zar.676520773@ucrmath> <231b3678.676527511@fergvax>
Date: Sun, 16 Jun 91 02:01:52 GMT

In article <231b3678.676527511@fergvax> 231b3678@fergvax.unl.edu (Phil Dietz) writes:

>Couldn't the terminal screen be double-buffered?  Like it'll scroll nasty
>on a hidden screen, then swapped, giving a nice jitter-text-free display.
> 
>True, You probably won't be able to go beyond 2400 bps (you'll be drawing
>and swaping like crazy), but at least it will satisfy those people used to
>IBMs etc. that dont flicker.
> 

Actually, it COULD be done at speeds above 2400 as well.  There's a few
solutions that jack could consider.  One would be to use direct blitter
access through the hardware for the screens (of course it won't conflict
with other programs blitter use because he would make sure blitter busy
wasn't set.  More importantly, programs running in the background would
probably not require much blitter use, since it is generally used for
screen updates etc)  In addition, by using an interleaved bitmap screen,
he would also get rid of that annoying flicker since all bitplanes are
moved in one blit. (it's also considerably faster doing blits this way)

 
For those with the extra ram, he could add an option to also enable double
buffering to ensure no color flicker.
 
An optimal solution might be to avoid the blitter altogether for moving
the screen, and just use a wraparound bitmap by using the copper to do
all the work.  The blitter/68000 could be used simply for putting the
characters on the bitmap.  This would definitely be the fastest solution.

>---- Flame Proof
>     o   __     |  o    Shield of                        Phil Dietz
>    +-- <__<    | -+-   Arrogance          231b3678@fergvax.unl.edu
>    /\          | / \                        University of Nebraska


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