Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!lll-winken!aunro!alberta!herald.usask.ca!regina!hercules!cazabon From: cazabon@hercules (Charles Cazabon (186-003-526)) Newsgroups: comp.sys.amiga.graphics Subject: Re: Idea for a graphics board Keywords: 24 bit Message-ID: <484@regina.uregina.ca> Date: 30 May 91 09:17:07 GMT References: <1991May28.191019.13406@nntp-server.caltech.edu> <479@regina.uregina.ca> <1991May29.212315.27847@nntp-server.caltech.edu> Sender: news@regina.uregina.ca Reply-To: cazabon@hercules.uregina.ca (Charles Cazabon (186-003-526)) Organization: University of Regina, Regina, Saskatchewan Lines: 53 In article <1991May29.212315.27847@nntp-server.caltech.edu> nygardm@nntp-server.caltech.edu (Michael T. Nygard) writes: :I've been looking at some numbers on the board. Here's what I came up with. : :Without using a CLUT (yuk.), assuming 80ns RAM, 1024x1024x24 resolution. : :1/(1024*1024*24*60) = .66227 ns/bit. :(80 ns/cycle) / (.66227 ns/bit) = 120.8 bits/cycle : :That means a bus _at least_ 128 bits wide. A 128 bit bus results in 5% of :the memory cycles availible for the processor. I know that you can get 60ns ram pretty cheap (almost as cheap as 80ns), and there are faster ram out there for a little more money (40ns, for instance). You could probably cut the bus down to 64 bits this way. Colourburst uses a 48 bit bus if I am not mistaken. I think it would be easier to have your own memory on board and let the graphics processor handle it at max speed. Perhaps something on the card to do DMA in a blitter-like way? :Unless I go to video RAM, things could get unreasonable very fast. :I know little about video RAM, could someone fill me in? : :Other problems: :I hadn't planned on this ever being a commercial product. Getting the kind :of printed circuit board this would require in single quantity would be very :expensive. : :As for the cost estimate, it's hard to say. Could be real high, maybe not. :There are too many factors at this stage (early design stage). No less than :$1000 for a one-of-a-kind. Now if we could put together a few people... Not one of a kind. To lay out the circuit board, and have 20 printed up, would probably only cost twice as much as a single board. Also, you could get parts a lot cheaper in 20x quantities. Perhaps you should take orders over the net, ask for a deposit, once you have a breadboard somewhat working. Or at least a semi-complete design. I have a high-tech friend who could field answers for you on just about any electronic/video/computer subject. Just email me the questions at cazabon@hercules.cc.uregina.ca (or is it cazabon@hercules.uregina.ca?). I will pass them on...he is great at designing his own stuff. Perhaps if you did a schematic, he could lay out the circuit board for you. He also works reasonably cheaply. This could be the beginning of a new era. You know there is a market for a $1000 or $1500 board of this type. I figure you could sell 1,000 boards in the first year. If you made $300 a board, you could be a rich man, and quick! I will gladly help out in any way I can...research on obscure topics, parts sourcing, etc. Contact me for details (I work free for the good of the Amiga community). --Chuck Cazabon, cazabon@hercules.cc.uregina.ca * My Opinions Are Not My Own...Feel Free To Plagiarize