Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!agate!shelby!rutgers!cbmvax!cbmehq!cbmger!peterk
From: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Simple Frame Buffer boards
Message-ID: <603@cbmger.UUCP>
Date: 30 Nov 90 17:15:51 GMT
References: <916@boing.UUCP>
Reply-To: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Organization: Commodore Bueromaschinen GmbH, West Germany
Lines: 26

In article <916@boing.UUCP> dale@boing.UUCP (Dale Luck) writes:
>
>Any kind of interface that forces the programmer to
>hit multiple i/o registers to peek and and poke pixels
>through a porthole just makes progamming more difficult.
>
>Is anyone doing a simple frame buffer board with VRAM
>to drive a reasonable resolution monitor with at least
>256 colors and a direct memory mapped raster? On the
>A3000 it could even be accessed 32 bits at a time to
>double the speed of operations.

I believe they fear to waste too much of the existing address
space of an A2000 when they want to use 24 (or at least 8)
bitplanes. The RAM has to be dual-ported for video access at
highest priority. And when it also has a digitizing part,
then it even has to be triple-ported. Perhaps they find this
too difficult (or too slow?).

But on the A3000, your argument is perfectly valid. With its
huge address space and its fast bus, there shouldn't arise
any real problems. (or?)

-- 
Best regards, Dr. Peter Kittel  // E-Mail to  \\  Only my personal opinions... 
Commodore Frankfurt, Germany  \X/ {uunet|pyramid|rutgers}!cbmvax!cbmger!peterk