[comp.sys.apple] protecting hard drives

lee@TIS.COM (Theodore Lee) (02/13/89)

Two questions came to mind while I was noting the flood of new
hard drive products now available --

a) is there any way of turning off any of the internal drives that are
now on the market? (I can't think physically of any clean way of doing
it since unlike the IBM boxes the apple case has no openings to the
inside from the outside.)

b) you'd think it would be pretty straight-forward to build a little
interface gadget between a SCSI drive and the cable that would allow
you to electrically disable write commands to a particular device
(I have never looked at the SCSI protocol so maybe it isn't that easy,
but it should be possible.)  Anyone know if anyone has such a thing?

(I agree with others who have commented on the absence of any
write-enable switch on hard drives, although somehow I vaguely
remember in some distant past reading about some kind of storage
media where you could lock out writes to particular regions of
the device; it may have been a mainframe disk or drum, however.)

labc-3dc@e260-3b.berkeley.edu (Andy McFadden) (02/13/89)

In article <8902121946.AA06399@TIS.COM> lee@TIS.COM (Theodore Lee) writes:
>Two questions came to mind while I was noting the flood of new
>hard drive products now available --
>
>a) is there any way of turning off any of the internal drives that are
>now on the market? [...]

This is becoming increasingly important as viruses spread... obviously on
the GS you can kill it from the control panel (although an intelligent virus
can turn it back on...), but the //e does create difficulties.  It may be
possible to wire something into the interface slot (hold a certain line low,
etc.), but this sounds a little dangerous.

Note that it *is* possible to disallow write access to a ProDOS file (incl
subdirectories; not sure about volumes).  Check out the change permissions
command in Davex (mine is aliased to chmod; not sure what it should be...)

-- 
labc-3dc@widow.berkeley.edu (Andy McFadden)

shawn@pnet51.cts.com (Shawn Stanley) (02/14/89)

lee@TIS.COM (Theodore Lee) writes:
>(I agree with others who have commented on the absence of any
>write-enable switch on hard drives, although somehow I vaguely
>remember in some distant past reading about some kind of storage
>media where you could lock out writes to particular regions of
>the device; it may have been a mainframe disk or drum, however.)

The old Radio Shack hard drives had write-protect buttons on them.  I liked
that feature a lot...

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INET: shawn@pnet51.cts.com

bsherm@umbio.MIAMI.EDU (Bob Sherman) (02/14/89)

in article <8902121946.AA06399@TIS.COM>, lee@TIS.COM (Theodore Lee) says:
> 
> a) is there any way of turning off any of the internal drives that are
> now on the market? (I can't think physically of any clean way of doing
> it since unlike the IBM boxes the apple case has no openings to the
> inside from the outside.)
> 
There is a DA available for the GS written by Glen E Bredon that will
write protect ALL devices at the same time. This included the RAM5 as
well as hard drives etc. I don't know all where it is available, but I
do know it is in the download section of Miami's Big Apple.

-- 
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blochowi@cat28.CS.WISC.EDU (Jason Blochowiak) (02/15/89)

	I know nothing about the internal drives, and even less about hardware.
However: It might be possible to write-disable partitions on an Apple SCSI
card.

	Keith: Would it be ok to modify a DIBTAB so that the w field in the
device status byte would show that the drive cannot be written to? Or, for
that matter, would it be possible to set the online bit to show that the
device isn't even online? If this would work, would it work in future
revisions?



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		Jason Blochowiak (blochowi@garfield.cs.wisc.edu)
			"Not your average iconoclast..."
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