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From: miner@dino.cpe.ulowell.edu (Rich Miner)
Newsgroups: comp.sys.amiga
Subject: Amiga A1000 DMA cycles vs. Amiga B2000 DMA cycles
Message-ID: <1757@dino.cpe.ulowell.edu>
Date: Fri, 25-Sep-87 10:28:56 EDT
Article-I.D.: dino.1757
Posted: Fri Sep 25 10:28:56 1987
Date-Received: Sun, 27-Sep-87 01:05:55 EDT
Organization: University of Lowell
Lines: 10

Question for CBM Engineers, or anyone else in the know:

On an A1000 DMA cycle, initiated by a coprocessor plug in card, DTACK 
appears during the S4 68000 state.  On the B2000 DTACK appears much earlier
ie during S2 (only 20ns after the address strobe of the coprocessor DMA
cycle).   Is DTACK issued earlier on the B2000 than the A1000?  I realize that
that this behavior is still within the specified limits, but it just seems
so much faster than the A1000 that is was a surprise.
-- 
Rich miner@ulowell.edu  617/452-5000x2693  ULowell CPE Imaging Research Lab