Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!uunet!knuth!mjbtn!raider!elgamy!elg From: elg@elgamy.RAIDERNET.COM (Eric Lee Green) Newsgroups: comp.sys.amiga.graphics Subject: Re: Colorburst and Animation Message-ID: <00669529084@elgamy.RAIDERNET.COM> Date: 21 Mar 91 04:18:04 GMT References: <979@cbmger.UUCP> <13948@life.ai.mit.edu> <1991Mar15.193235.2926@cs.mcgill.ca> Organization: Eric's Amiga 2000 @ Home Lines: 23 From article <979@cbmger.UUCP>, by peterk@cbmger.UUCP (Peter Kittel GERMANY): > In article <1991Mar15.193235.2926@cs.mcgill.ca> tinyguy@cs.mcgill.ca (Yeo-Hoon BAE) writes: >> From quick calculation, 18 bits are more than enough to >> display 640x400 screen with every pixel having different >> colors. So why not have 24 bit palettes and use 18 bits > Indeed, 24-bit palettes were nice to have, BUT: Do you know one > existing chip that can hold that palette data (or color lookup > table)? Remember, you want 2^24 entries in your palette with > 18 bits each, this is, well, let's calculate, 48 Megabytes. > Umpf, a little much for a CLUT chip, or what? You've reversed what he was saying. He was saying that there's only 2^18 possible pixels on a 640x400 screen, so that there was no need for more than 18-bitplane resolution, indexing into a table of 24-bit values (for smooth color shadings and such). This would still require a fairly hefty lookup table (2^18 is 256K, so 256K * 3), but not as outrageous as the 48 megabytes that you quote. A 768K lookup table is within the realm of possibility, though not within the realm of affordability ( :-} ). -- Eric Lee Green (318) 984-1820 P.O. Box 92191 Lafayette, LA 70509 elg@elgamy.RAIDERNET.COM uunet!mjbtn!raider!elgamy!elg