Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!zaphod.mps.ohio-state.edu!think.com!snorkelwacker.mit.edu!shelby!neon!torrie
From: torrie@cs.stanford.edu (The Ghost Who Walks)
Newsgroups: comp.sys.apple2
Subject: Re: Mac LC VRAM
Message-ID: <1991Feb8.022047.23442@Neon.Stanford.EDU>
Date: 8 Feb 91 02:20:47 GMT
References: <1991Feb07.235919.24723@lynx.CS.ORST.EDU>
Sender: torrie@Neon.Stanford.EDU (Evan James Torrie)
Organization: Computer Science Department, Stanford University
Lines: 18

curfmanm@prism.CS.ORST.EDU (Matthew Curfman) writes:

>David Whitney writes:

>15 bits will allow the LC to produce 32,768 colors at a time.  Why they didn't
>use the 16th bit as a color bit, I don't know. What use is a one bit alpha
>channel for anything other than some kind of overlay hardware? 

  Apple's colour model is RGB, i.e. 3 components.  15/3 = 5 bits for each.
16/3 = 5.33333 bits for each.  My guess is that 32-bit QuickDraw (which is 
what model the 15-bit colour is using), assumes that each component is
the same size.

-- 
------------------------------------------------------------------------------
Evan Torrie.  Stanford University, Class of 199?       torrie@cs.stanford.edu   
"If it weren't for your gumboots, where would you be?   You'd be in the
hospital, or in-firm-ary..."  F. Dagg