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From: grr@cbmvax.UUCP
Newsgroups: comp.sys.amiga
Subject: Re: The Future of Amiga Video
Message-ID: <2642@cbmvax.UUCP>
Date: Wed, 28-Oct-87 07:02:35 EST
Article-I.D.: cbmvax.2642
Posted: Wed Oct 28 07:02:35 1987
Date-Received: Sat, 31-Oct-87 09:47:34 EST
References: <4579@zen.berkeley.edu> <2987@xanth.UUCP>
Reply-To: grr@cbmvax.UUCP (George Robbins)
Organization: Commodore Technology, West Chester, PA
Lines: 44
Keywords: make my day, Commodore!

In article <2987@xanth.UUCP> kent@xanth.UUCP (Kent Paul Dolan) writes:
> 
> [see reference for context - surely you read it!]
> 
> Please, please, PLEASE, not EIGHT bits per pixel, OK?  Six is good,
> nine is great(!), but eight means that all my software to divide up
> the color palatte nicely is a mess.  Can't we give each gun the same
> number of bits of resolution?  Since we give each bit plane its own
> portion of memory anyway, there is no reason to aim at fitting the
> bits in a pixel per byte.  In 1978, the last time I bought a high end
> workstation (a few RAMTEKs, if you're curious) the state of the art in
> color look-up tables was 11 bits in, and they were straining really
> hard to get to twelve.  Nine doesn't seem like it should be much of a
> challenge 9 years later.  It may require interleaved memory access
> from the video side; I don't know enough about the hardware to do the
> calculations.

Hmmm, you seem to trying to ignore the color lookup table for a direct
relationship of bitplanes to color guns.  The current Amiga bus would
let you fetch 8 bit planes, adding that 9'th would require doubling
the bandwidth.  If at sometime we give you 8, we'll let you use 6 if
you want  8-).

Sure, when cost is no object as in a high-end graphics terminal you can
have all the bit planes you want, however the essense of the affordable*
Amiga was compromising features with what could be reasonably integrated
into the basic chipset.

* affordable - the A1000 was an end-product of the Amiga development
  effort, not neccessarily the cost target the chipset was designed for.

> On the output side, the only limitation seems to be what you want to
> support in the way of D/A video-speed converters.  Eight bit ones have
> obviously been around for a long time, or 24 bit frame buffers would
> be a joke.  Are they very expensive?

Well, at least several times more expensive than the implementation in the
A1000 or A500.  All that nice Brooktree stuff is rather expensive, the
Inmos parts begin somewhat more reasonable.

-- 
George Robbins - now working for,	uucp: {ihnp4|rutgers|allegra}!cbmvax!grr
but no way officially representing	arpa: out to lunch...
Commodore, Engineering Department	fone: 215-431-9255 (only by moonlite)