joslinpr@WPAFB-FDL.ARPA (10/06/87)
A recent letter complained that this newsgroup is used only to bitch at Atari for their marketing sins. Fair enough. If some of the tech-types at Atari wouldn't mind talking about their work, I have a few questions. 1) Why is video memory organized the way it is? Wouldn't it be easier to use 'chunked' (ie contiguous nibble or byte per pixel)? I know that this way the different screen resolutions would have taken different amounts of video memory, but even the 640x400 screen would have taken 'only' 128k at a nibble per pixel. Did the scheme used make the video shifter or blitter easier/cheaper? 2) We've heard all sorts of (mostly unqualified) numbers about how much the blitter will speed up the ST. Early rumors said 3-16X improvement; later rumors added the caveat 'on screen intensive operations'. What does the blitter really buy you? Does the CPU continue to process in parallel, making the blitter a kind of dma (perhaps with logical operations during the transfer)? If the CPU is just transferring blocks of memory, isn't the memory access time the limiting factor? How can the blitter be any faster? Will the blitter also be a graphics processor, able to draw lines and circles, given endpoints? Please reply to the newsgroup if you think others might be interested. Thanks Paul Joslin joslinpr@wpafb-fdl.arpa /------------------------------------------------------/ / (UPI) A leading Democratic Presidential Candidate / / today announced an ambitious plan to repeal the / / Law of Gravity. "After all", he said, "It / / unfairly discriminates against those of greater / / mass." A Republican Candidate ridiculed the idea, / / saying, "This is another example of the government / / interfering where is doesn't belong. Let the free / / enterprise system correct these imbalances". / /------------------------------------------------------/