Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!rutgers!usc!wuarchive!kuhub.cc.ukans.edu!markv
From: markv@kuhub.cc.ukans.edu
Newsgroups: comp.sys.amiga.tech
Subject: Re: Simple Frame Buffer boards
Message-ID: <27270.275e207b@kuhub.cc.ukans.edu>
Date: 6 Dec 90 16:42:03 GMT
References: <916@boing.UUCP> <23699@grebyn.com> <918@boing.UUCP> <1411@mpirbn.mpifr-bonn.mpg.de>
Organization: University of Kansas Academic Computing Services
Lines: 36

> In article <918@boing.UUCP> dale@boing.UUCP (Dale Luck) writes:
>>I think the benefit far out weighs the cost.
>>I'd be glad to give up 1/8 of my
>>address space for a 1024x1024x8 frame buffer board. I think
>>it is a very small price to pay. I just don't see that many
>>people unwilling to give up 1M-2M of memory. It still leaves
>>4-6 megs of memory for programs as well as the 1M of chip memory. 
> Hmm, I can't see much benefit from this besides ease of programming.
> IMHO, it is sufficient to map a smaller rectangular part. The drawing
> routines can be adapted without much peformance loss.

Well, if the board's memory can be used as normal system memory when
not being used as a frame buffer...?  This might be a nice compromise
and certainly would have its marketing strong points ("Get a 2MB
memory expansion and frame buffer in one...").

I've had to deal too much with
VGA and EGA progrmaming where everything has to be done through either
I/O ports, or a limited area of memory.  It works, and you dont take
too much of a performance hit, but its a pain in the *bleep*.

Having the whole buffer available certainly is nice, but not
essential.  However, if the buffer is bitplane oriented (and not
"chunky" pixel), then having enough of an address window for one whole
bitplane at once is certainly sufficient and a good compromise.

> Michael van Elst
-- 
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