Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!genrad!panda!talcott!harvard!seismo!rochester!pt.cs.cmu.edu!wb1.cs.cmu.edu!wrs
From: wrs@wb1.cs.cmu.edu (Walter Smith)
Newsgroups: net.micro.mac
Subject: Re: HFS compatability and Software backup - Simple solutions
Message-ID: <258@wb1.cs.cmu.edu>
Date: Wed, 22-Jan-86 11:11:43 EST
Article-I.D.: wb1.258
Posted: Wed Jan 22 11:11:43 1986
Date-Received: Sun, 26-Jan-86 05:29:51 EST
References: <1636@Shasta.ARPA> <348@ccivax.UUCP>
Distribution: net
Organization: Carnegie-Mellon University, CS/RI
Lines: 19
Summary: Hardware manual says locking is software

In article <348@ccivax.UUCP>, guest@ccivax.UUCP (What's in a name ?) writes:
> I was just wondering... An article on the net several months ago hinted that
> write-protecting a disk (with the tab in the upper left corner) didn't REALLY
> protect the disk; that it was up to the software to ask the OS if the disk
> was locked; that if the s/w didn't ask, the disk could be written to whether
> or not it was locked.    DOES ANYONE IN NETLAND KNOW IF THIS IS TRUE?????
> 
> 
> Sam Mantel -- Roch, NY

According to the Hardware Manual, the IWM has a status bit indicating that
the disk is locked.  It says to be sure to check this bit before writing to
the disk.  I would think this was done at the disk driver level, but there
seem to be cases of applications writing to locked disks, so...

-- 
      Walter Smith, CS undergraduate, Carnegie-Mellon University
uucp: ...!seismo!cmu-cs-k!wrs		       arpa: wrs@cmu-cs-k.ARPA
	    usps: 5141 Forbes Ave.; Pittsburgh, PA  15213