Path: utzoo!attcan!uunet!snorkelwacker!apple!motcsd!dms!rotberg
From: rotberg@dms.UUCP (Ed Rotberg)
Newsgroups: comp.sys.mac
Subject: Re: Mac IIfx Quesitons
Message-ID: <1021@dms.UUCP>
Date: 26 Mar 90 18:43:25 GMT
References: <8799@chaph.usc.edu>
Organization: Atari Games Inc., Milpitas, CA
Lines: 26

From article <8799@chaph.usc.edu>, by talcott@nunki.usc.edu (Adam Talcott):
> The ad also says, "...the new Apple 24-bit color card...gives you the ability
> to work with as many as 16.8 million colors..."
> 
> Question: How many can it display at one time?

Geez, I always love those claims of 16.7 million colors at once!  This is
definitely the bread and butter stuff of marketing and ad types (read as
suits).  In fact, on the standard Mac RGB monitor, no video board will be
capable of displaying more than 307,200 colors at once!  That is because
there are only 307,200 pixels on the screen (640x480).  In order to
be able to display 16.7 million colors at once, you would need a monitor
with a resolution of 4096x4096 pixels.

What is really going on is that with direct color (24-bit color) each pixel
specifies its RGB (or HSV) value without reference to a color-lookup table
(CLUT or palette).  This allows a screen image to display any ONE of
16.7 million colors at each pixel.

So the answer to your question of how many it can display at once is really
307,200.  If you go with a SuperMac 24 bit board that has more resolution
(i.e. 1024x768) or something you can display up to number of pixels supported
by that hardware, each in a different color.  That's not to say, however,
that you would be able to visually distinguish between each individual color...

	- Ed Rotberg -