Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!lll-lcc!ames!ucbcad!ucbvax!CORY.BERKELEY.EDU!dillon From: dillon@CORY.BERKELEY.EDU (Matt Dillon) Newsgroups: comp.sys.amiga Subject: : Re: Great big huge floppy disk? Message-ID: <8612270158.AA04712@cory.Berkeley.EDU> Date: Fri, 26-Dec-86 20:58:48 EST Article-I.D.: cory.8612270158.AA04712 Posted: Fri Dec 26 20:58:48 1986 Date-Received: Sat, 27-Dec-86 00:45:11 EST Sender: daemon@ucbvax.BERKELEY.EDU Organization: University of California at Berkeley Lines: 15 >> >>... The blitter is used to decode [data from the read track], >>usually a sector at a time, and it achieves this decoding in one >>blitter pass (though as I recall, it takes three passes to encode the data). > > Which explains why copying disk to RAM: is so much faster than RAM: >to disk. (I have a single drive system -- could you tell?) > Well... actually that's not the reason. The reason is that when you are writing to disk, the data on the track must first be READ, then re-written (since you are not modifying the ENTIRE track, only several sectors on that track). -Matt