jan@looking.UUCP (Jan Gray) (02/05/86)
In article <12180482042.28.G.DYER@SU-SCORE.ARPA> G.DYER@SU-SCORE.ARPA (Landon Dyer) writes: > >There are two 250ns windows. One window is for "static" system requests >(video DMA and memory refresh). The other window is available for disk >DMA, blitter DMA, and processor accesses. Refresh cycles are done during ^^^^^^^^^^^ >horizontal and vertical blank (and take, say, 5% of the first window). >When the first window is not being used, it is available to fill requests >that would otherwise go to the second window. WHAT BLITTER????? Somewhere in the documentation I saw an interrupt vector for "gpu blt done"...but nothing else! I can't believe there is special hardware for bitblt on the ST, since vro_cpyfm() is too damn slow(*). Unless, of course, the "blitter" is only useful for doing no-skew, whole word transfers... Please please please tell us more. Maybe you could even fill us in on how to do bitblt from the line A vector (since my documentation (and others) were missing the last n pages of the "Long Awaited Line A Document"). Thanks, Jan Gray Looking Glass Software, Waterloo Ont. (519) 884-7473 p.s. Are you *the* l. dyer who wrote the BIOS, etc (or at least had his name on the listings?) (*) That is, for doing large image processing tasks like "spreading" the screen, running life on the whole screen etc. (BTW, can anyone beat 400,000 life cell-generations per second on their ST?)