Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!sco!brianm
From: brianm@sco.COM (Brian Moffet)
Newsgroups: comp.sys.amiga
Subject: Re: BlackBelt may not be a great solution.
Message-ID: <4351@scolex.sco.COM>
Date: 9 Jan 90 17:48:20 GMT
References: <5965@sdcc6.ucsd.edu> <5326@tekig5.PEN.TEK.COM>
Sender: news@sco.COM
Reply-To: brianm@sco.COM (Brian Moffet)
Organization: The Santa Cruz Operation, Inc.
Lines: 25


In article <5326@tekig5.PEN.TEK.COM> waynekn@tekig5.PEN.TEK.COM (Wayne Knapp) writes:
>
>Also I have some doults as to how well it is going to work for animation.
>The main problem is the color palette.  256 colors * 3 bytes per color is
>2048 bytes.  A 704 x 480 hi-res screen uses 88 bytes per line which means
>that it takes about 24 lines plus whatever overhead to load the palette.

Whoa!  Think about what you are saying.  Yes, it takes 3 bytes to
load a palette register on the Black Belt.  However, this does not
take 8 pixels.  a byte of data is only 2 pixels (4 bitplanes x 2 pixels)
so it only take 6 pixels per palette register.

Given your example of 704 horizontal resolution, it would only take
at most 3 scan lines.  (about 116 registers per scan line.)
for a normal screen it would only take 3 scan lines as well (106 / line)

This to me is completely reasonable.  I could quite happily
live with a 320x196 of 320x396 screen in "normal" not overscan modes.
And, I intend to buy one of these things for my amiga when it comes out.
I would probably figure out overscan and set up 3 extra lines of data to
deal with the special data for the Black Belt Card.  I have a gif
viewer almost ready for it :-)

brian moffet