Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!asuvax!noao!stsci!schiffer
From: schiffer@stsci.EDU (Skip Schiffer)
Newsgroups: comp.sys.apple2
Subject: Re: Help with my 5.25 drive
Summary: Drive and Write Electronics Independent
Message-ID: <2520@stsci.EDU>
Date: 18 Apr 91 14:53:49 GMT
References: <29110018@hpfcdj.HP.COM> <1991Apr6.085456.19804@nntp-server.caltech.edu>
Reply-To: schiffer@stsci.EDU (Skip Schiffer)
Organization: Space Telescope Science Institute, Baltimore, MD 21218
Lines: 20

toddpw@nntp-server.caltech.edu (Todd P. Whitesel) writes:

> If the drive motor isn't spinning, the disk
>can't be modified -- IF the drive electronics are working properly.

Although this statement is correct (with the IF clause) it is true that in
the Apple drives the write electronics and the motor electronics are 
independent.  It is possible to activate the write without enabling the
motor.  (In fact it is possible to enable the write without addressing the
drive if the electronics fails the "proper" manner.)  I spent more than a
week proving this problem with a defective Apple 5.25" drive approximately
6 years ago.

		Just to keep the record straight.
			Skip

-- 
| F. H. Schiffer 3rd              |                            |
| schiffer@stsci.edu              | I speak for myself alone.  |
| scivax::schiffer                |                            |