Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!think.com!samsung!emory!gatech!ncsuvx!news From: kdarling@hobbes.ncsu.edu (Kevin Darling) Newsgroups: comp.sys.amiga.hardware Subject: Re: Video hardware hack Keywords: 24 bits, video, hardware hack Message-ID: <1991Jan24.175227.10878@ncsuvx.ncsu.edu> Date: 24 Jan 91 17:52:27 GMT References: <775@cbmger.UUCP> Sender: news@ncsuvx.ncsu.edu (USENET News System) Organization: NCSU Computing Center Lines: 34 peterk@cbmger.UUCP (Peter Kittel GERMANY) writes: > How about 24-bit colors by a truely simple hack? [...description] I think you've almost described the HAM-E. As I understand it, it uses the 640x4-bit mode, and combines the nybbles into 320x8-bits. That gives 256 choices/pixel, and those index into a palette system which outputs 8-bits each on R/G/B to the D/As. (They also got fancy, and have a HAM-like mode... but with 18 bits instead of 12 bits... for 262K colors instead of standard 4K colors. A coming upgrade will give 640x256colors, but I sure don't know how!) A special code sequence in the first line(s) of a picture is what triggers it to read in a palette set and/or use the HAM-E modes. A full zero line untriggers it (so that the blank lines between screens allow normal Amiga mode screens to be pulled up or mixed). That also means normal IFF display programs can be used. Clever. > By now there are new things available. I mean that CEG chip by Edsun. > It works as a CLUT (color lookup table) plus three 6-bit DACs. [...] > I think this CEG chip will become quite common in the PC world, > so we should have an answer for it on the Amiga. (Or are there > different opinions?) I think CBM could make a video card using more popular components, yes. For instance, on the MM/1 we used a standard Brooktree 8-bitRGB palette chip, and so can easily drop in much neater chips (like the anti-aliasing smart palette chips, or the windowing pal chip, etc). It's a lot easier to "catch up" when you can take advantage of PClone research ;-). This route also requires weening Ami programmers away from non-independent gfx diddling... and that could be difficult (the Amiga and IBM worlds are almost in the same boat here). Still, it'll have to be done sooner or later (the weening, not the chip changes). - kevin