Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!brutus.cs.uiuc.edu!psuvax1!rutgers!uwvax!umn-d-ub!umn-cs!davidli From: davidli@umn-cs.CS.UMN.EDU (David Paschall-Zimbel) Newsgroups: comp.sys.atari.st Subject: Re: Mac II screen colors (Was: Genlock Inquiry) Summary: 16 million "simultaneous" = ridiculous Message-ID: <18107@umn-cs.CS.UMN.EDU> Date: 9 Jan 90 16:32:30 GMT References: <9001091511.AA13450@ucbvax.Berkeley.EDU> Reply-To: davidli@umn-cs.cs.umn.edu (David Paschall-Zimbel) Organization: Flying Taoist Graphics Lines: 36 In article <9001091511.AA13450@ucbvax.Berkeley.EDU> MBERNAR@ERENJ.BITNET (Marcelino Bernardo) writes: >You're dead wrong on this one. The Mac II series does provide for 16.7 >million colors. Whether you get it or not depends on the video display >board installed on the Nubus. In front of me is an ad from Radius for >their DirectColor/24 which can simultaneously access every one of the Mac's >16.7 million colors. They also make a 16-bit board (32,768 colors simul- >taneously) and 8-bit board. Now let's see, what sort of video display unit do we need? 16 million colors displayed simultaneously would imply 16 million pixels, or a resolution of 16000 x 1000 pixels, or 8000 x 2000 pixels, or 4000 x 4000 pixels. Considering that such video display units do not appear to exist in the real world today (if you _do_ know of one, by all means give the address of the vendor -- and the price!), I highly doubt that there is a display which can show all 16 million colors "simultaneously". As an aside, consider that each pixel requires 24 bits (or 3 bytes). The DISPLAY MEMORY alone would be 48 megabytes in order to display 16 million colors "simultaneously". What can we therefore conclude? Although 24-bit Color is possible on a Macintosh, using non-Apple hardware, there are no Macintosh computers which can currently display 16 million colors on screen simultaneously. The standard operating system limit is 256 (ie. buy Apple monitor and RAM card). In order to be able to display 16 million colors on screen at the same time would require investment in 48 megabytes of memory (at $100 / meg this is about $5000), AND use of a video display with a minimal resolution of 4096 x 4096 pixels. I expect that the display would cost more than the memory (by a long shot). -- David Paschall-Zimbel On second thought, the display device probably does exist -- given all of the wondrous CAD/CAM systems which one can purchase ... but then why bother with a Macintosh when the 'real thing' probably doesn't cost much more?