Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!samsung!uunet!cbmvax!hood From: hood@cbmvax.commodore.com (Scott Hood) Newsgroups: comp.sys.mac.misc Subject: Re: 24-bit color Message-ID: <16343@cbmvax.commodore.com> Date: 6 Dec 90 16:29:44 GMT References: Reply-To: hood@cbmvax.commodore.com (Scott Hood) Organization: Commodore, West Chester, PA Lines: 46 In article peirce@outpost.UUCP writes: > >In article <6110@crash.cts.com>, bill@pro-gateway.cts.com (Bill Long, SysOp) writes: >> >> I'm an Apple II user and try to somewhat keep up with the Mac world, and I >> have a couple of questions about 24-bit graphics. >> >> 1) Why is 24-bit better than 32-bit? > >24-bit isn't better than 32-bit. 32-bit color is 24-bit color plus 8-bits >for an alpha channel. Since Apple hasn't defined what the alpha channel >is suppose to do (though some third parties have), this extra 8-bits >of data isn't used by video cards. Often these two terms are used >interchangeably. > > >> 2) How many of the 16 million colors can be on-screen at once? > >With 24-bit color each pixel can fully specify a color (8 bits of >red, blue, & green) so you can display as many colors on the screen >as you have pixels. > >-- michael > > >-- Michael Peirce -- {apple,decwrl}!claris!outpost!peirce >-- Peirce Software -- Suite 301, 719 Hibiscus Place >-- Macintosh Programming -- San Jose, California 95117 >-- and Consulting -- (408) 244-6554 Are you assuming that the system in question has had it's video memory expanded to several megabytes? I thought that the Apple 8*24 card only had enough standard memory to display 256 colors out of the 24-bit palette on the screen at once. Am I missing something? It is very nice indeed that once you have spent more money upgrading the video memory of the display device that you can display and seriously use as many colors as you have pixels out of the full 24-bit palette. Scott Hood -- -- Scott Hood, Hardware Design Engineer (A3000 Crew), Commodore-Amiga, Inc. {uunet|pyramid|rutgers}!cbmvax!hood hood@cbmvax.cbm.commodore.com "The views expressed here are not necessarily those of my employer!"