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From: prindle@nadc
Newsgroups: net.micro.cbm
Subject: Write protect on a 1541 drive
Message-ID: <3002@caip.RUTGERS.EDU>
Date: Fri, 8-Aug-86 16:31:09 EDT
Article-I.D.: caip.3002
Posted: Fri Aug  8 16:31:09 1986
Date-Received: Sat, 9-Aug-86 11:17:13 EDT
Sender: daemon@caip.RUTGERS.EDU
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 22

From: prindle@NADC

Stupid question of the week:

	Is it possible to "write" on a diskette inserted into a 1541 when the
	write enable notch is properly covered?  I once tried to bypass the
	DOS routines and just set the head to "write" mode by going directly
	to the I/O port; with the write enable covered, it went through all
	the motions, but did *not* write on the diskette.  Thus I've always
	assumed an electrical interlock is built in.

The reason I ask is that a friend had his "1541 physical exam" diskette in
the drive (this diskette has *no* notch whatever), had the drive on it's side
was not protected), with track 18 totally wiped!  He swears there were no
magnetized screwdrivers in the vicinity.  He subsequently got the drive
reasonably aligned without the now-defunct alignment disk and was able to
read and write other diskettes normally!

So, how could it happen.  Any clues?

						Frank Prindle
						Prindle@NADC.arpa