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From: berry@tolerant.UUCP (David Berry)
Newsgroups: net.micro.mac
Subject: Re: Re: 800k drives faster?
Message-ID: <254@tolerant.UUCP>
Date: Mon, 27-Jan-86 18:10:17 EST
Article-I.D.: tolerant.254
Posted: Mon Jan 27 18:10:17 1986
Date-Received: Sat, 1-Feb-86 02:32:33 EST
References: <216@a.UUCP> <26700048@inmet.UUCP>
Organization: Tolerant Systems, Inc.  San Jose, CA
Lines: 18

According to something I saw somewhere (delphi I believe) the 800K drives
appear faster because the drive speed and seeking, etc is all performed
by a processor in the drive rather than being performed by the Mac's 68K,
thus allowing more coprocessing to happen.  In addition the drive can now
tell the 68K when it is up to speed and ready to transfer rather than the
68K having to watch the drive and figure out when it seems to be ready.

BTW, it isn't clear to me how well all this is going to work with copy
protection schemes which work by stuffing strange numbers in to the PWM
that controls disk rotation speed.  Since this is no longer used (the
information is fed to the drive processor, which controls the rotation
speed) I suspect it may break them.
-- 

	David W. Berry
	{ucbvax,pyramid,idsvax,bene,oliveb}!tolerant!berry

	I'm only here for the beer.