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From: nygardm@nntp-server.caltech.edu (Michael T. Nygard)
Newsgroups: comp.sys.amiga.graphics
Subject: Re: Idea for a graphics board
Keywords: 24 bit
Message-ID: <1991May29.212315.27847@nntp-server.caltech.edu>
Date: 29 May 91 21:23:15 GMT
References: <1991May28.191019.13406@nntp-server.caltech.edu> <479@regina.uregina.ca>
Organization: California Institute of Technology, Pasadena
Lines: 31

I've been looking at some numbers on the board.  Here's what I came up with.

Without using a CLUT (yuk.), assuming 80ns RAM, 1024x1024x24 resolution.

1/(1024*1024*24*60) = .66227 ns/bit.
(80 ns/cycle) / (.66227 ns/bit) = 120.8 bits/cycle

That means a bus _at least_ 128 bits wide.  A 128 bit bus results in 5% of
the memory cycles availible for the processor.

Unless I go to video RAM, things could get unreasonable very fast.
I know little about video RAM, could someone fill me in?

Other problems:
I hadn't planned on this ever being a commercial product.  Getting the kind
of printed circuit board this would require in single quantity would be very
expensive.

As for the cost estimate, it's hard to say.  Could be real high, maybe not.
There are too many factors at this stage (early design stage).  No less than
$1000 for a one-of-a-kind.  Now if we could put together a few people...

This probably belongs in .hardware, but it started here, and I think the
main interest is here.

Free free to contact me if you have suggestions (or would like to help!)

-- 
--------
Mike Nygard
nygardm@coil.cco.caltech.edu