Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!uunet!cbmvax!raible
From: raible@cbmvax.commodore.com (Bob Raible - LSI Design)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga Chips/Comp.Sys.Amiga.Tech
Message-ID: <16696@cbmvax.commodore.com>
Date: 20 Dec 90 17:17:55 GMT
References: <39640@nigel.ee.udel.edu>
Reply-To: raible@cbmvax.commodore.com (Bob Raible - LSI Design)
Organization: Commodore, West Chester, PA
Lines: 68

In article <39640@nigel.ee.udel.edu> Papushka@student.umass.edu writes:
>To all you people out there from C= in West Chester:
>
>I'm not a very technical person, as many of the Amiga users are.
>Yet, all of us tend to wonder just how easy/difficult it would be to
>build a new, rather low-cost custom chip-set that would be:
>A) Backwards compatable with the current chips
>B) Adress either 24 bit color or some variation (a higher resolution with
>more colors.. .at least up to VGA standards
>
>I've read many posts from you at C=, which seem to say that the current
>(original) chipset is so set in its ways (no pun intended) that is nearly
>impossible to build into the Amiga a higher standard of graphics and
>sound without creating an entirely new machine.
>
>So, my question I guess boils down to this:
>Is it possible at all for you engineers to produce, within a reasonalbe
>amount of time, a new custom chipset for the Amiga that is backwards
>compatable with earlier (current) versions and software and yet sports
>features (more sound voices/16 bits... more colors) that are superior
>to today's standard Amiga equipment?
>
>Any reply would be appreciated. (If my original post does get through
>the relay alive..... <sigh>)
>
>-Paul Antico / University of Massachusetts at Amherst.
>"We use Cybers and can't stand 'em"

	Instead of replying to your post point by point, I decided to
try to answer this in more general terms. We are of course aware that
many users desire more colors and higher resolutions. Ham is useful but
has its limitations. The features you specifically asked for are
reasonable and quite implementable(assuming 24 bit color is referring to
palette and not bits per pixel). The costs can probably be controlled to
a reasonable level, even though chip cost would be certain to rise
somewhat. There are certain factors about the Amiga architecture that
stymy rapid introduction of new custom chips. First we have a bitplane 
architecture unlike our competion, and this prevents us from taking 
advantage of off the shelf solutions to accelerate the process.
Secondly, the upgrade path is difficult due the generality of the Amiga
programming model. For example you can't just can't drop in VRAM to
accelerate graphics due to alignment issues. According to the model
bitplanes could be located anywhere in chip RAM, and even overlap. True,
most applications let the llibraries handle memory allocation, but
that's not universally true. Compatibility would dictate that we try to
maintain as much generality as possible. Coiming up with suitable
enhancements is not always easy and take time to develop. Third, the
custom chips are designed in older technology, and need to be redesigned
in a more suitable process. Nothing we can't handle, just takes time.
Finally, we need to design a chip set that is economical enough to be
put in low end Amigas for starving students(believe me, I've been
there), but has the ability to handle the needs of power-mad ray-tracers
and their ilk. So system definition takes time too. If there were any
shortcuts, believe me we would have taken them already.

	I have been following this group rather closely for the last
year or so(well actually I skip over a lot, but then you'd probably want
me to spend as much time as possible on chip design :3) )! In that time
I can't recall anybody from here claiming that we couldn't carry the
Amiga forward. I think that you may just be misinterpreting a little
healthy pessimism(there's a wall in our path, but it ain't brick - more
like gypsum and 2x4's). 

	Don't forget there's all kinds of boards out there that can
offer higher colors at higher resolutions. The trick is to seemlessly
integrate the display into the Amiga environment. That involves system
design, extensive chip design, and a healthy dose of re-coding of 
graphics lib. Doing it right takes time. I hope I explained why.