Newsgroups: comp.sys.apple2
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!m.cs.uiuc.edu!knauer
From: knauer@cs.uiuc.edu (Rob Knauerhase)
Subject: Re: Nuking a hard drive
Message-ID: <1991Apr30.220118.7831@m.cs.uiuc.edu>
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Organization: University of Illinois, Dept. of Comp. Sci., Urbana, IL
References: <15212@darkstar.ucsc.edu>
Date: Tue, 30 Apr 91 22:01:18 GMT
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In <15212@darkstar.ucsc.edu> unknown@ucscb.ucsc.edu (The Unknown User) writes:
>	Could someone please tell me how to nuke my hard drive?

Sure.  Get a couple ounces of plutonium, and some VERY precise hammers...
Then stand back - BOOM.
    I can see it now: cars all over California with bumper stickers that
say "No Nukes - save Unknown's hard drive". :)

>	That is, what blocks I can zero so that NEITHER GS/OS NOR ProDOS
>can see it.

I think the key phrase here is "what blocks I can zero" -- the very idea of
_having_ blocks to zero means you're on a formatted drive.  Writing zeros to
them does nothing to the block headers themselves, let alone the drive's
internal partition table.

>	When I zero the first few blocks (which I thought was a reasonable
>thing to do), I can get Prodos 8 so it won't realize a device is there,
>but when I boot the Finder, it still recognizes the partitions, and
>I believe even fixes the blocks I zeroed out before!

The easiest way I can think of is to plug the thing into a Mac and let it
do its magic (Macs hate real filesystems <grin>).  I don't remember if there
are any utilities for the II that will scrag your drive or not (at least not
_intentionally_!).
    On all the AppleII-based SCSI drives I've seen, sending the SCSI low-level
format code (if there is such a thing, I'm not sure) returns instantly because
the drives are pre-formatted at the factory.  Some of the Mac utilities (like
the ones I got with my Hyperdrive) actually take 10+ minutes to low-level
format the drive; I don't know if they issue a SCSI command for it or if they
spell out for the drive exactly what it should do.

Rob
--
Robert C. Knauerhase            University of Illinois at Urbana-Champaign
"I get my exercise acting as    Dept. of Computer Science, Gigabit Study Group
 pallbearer for my friends      knauer@cs.uiuc.edu, rck@ces.cwru.edu
 who exercise..."               knauer@scivax.lerc.nasa.gov