Path: utzoo!attcan!uunet!cs.utexas.edu!rutgers!cbmvax!cbmehq!cbmger!peterk
From: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Newsgroups: comp.sys.amiga
Subject: Re: Better Amiga Graphics
Message-ID: <294@cbmger.UUCP>
Date: 18 Jul 90 07:08:20 GMT
References: <24825@snow-white.udel.EDU>
Reply-To: peterk@cbmger.UUCP (Peter Kittel GERMANY)
Organization: Commodore Bueromaschinen GmbH, West Germany
Lines: 35

In article <24825@snow-white.udel.EDU> TSA91@ccvax.iastate.edu (Marc Barrett) writes:
>   The discussion about improving the Amiga has centered around the idea
>of adding 24 (or even 32) bitplane graphics modes to the Amiga.  I, for
>one, do not think this should be done.  To add such resolution modes
>would just turn the Amiga into a clone of the MAC II, and sacrifice any
>edge that the Amiga has in animation capabilities.

I don't think only the MAC II is able to do 24-bit graphics. So this 
single criterium wouldn't make the Amiga a MAC clone already.
 
>   The HAM mode, as it is now, has one main disadvantage: the color
>'fringing'that results from the HAM mode's inability to make sharp
>color transitions.  This can be allevaited substantially by increasing
>the number of registers and the horizontal resolution.  A 10-bitplane
>HAM mode would have 256 registers, enough to alleviate the color
>fringing substantially.  Increasing the horizontal resolution of the
>HAM mode would also cause the fringing to be far less noticeable.

I fiddled a bit with the numbers. If you leave the resolution for
every color at 4 bits (which gives still 4096 colors total), then
you could do another nice trick with 10-bitplane HAM: 
Instead of changing only one of the three colors, you now could change
2 for every pixel! To figure it out: to select 2 colors (to change)
out of 3 gives again 3 possibilities (12, 13, 23) plus one Null term
for no change ( = direct color table). So again 2 bits do for selection
of these 4 cases, leaving 2 x 4 bits in 10 bitplanes for the new color values.
This would make 4096 color HAM pictures nearly flawless.

And when they in (far?) future make the Amiga custom chips really 32-bit,
they should be able to double bandwidth making these more bitplanes
possible. Would be really nice.

-- 
Best regards, Dr. Peter Kittel      //     E-Mail to 
Commodore Frankfurt, Germany      \X/      rutgers!cbmvax!cbmger!peterk