[TUHS] PDP-11/70 SPL (was: Early non-Unix filesystems?)

William Pechter pechter at gmail.com
Tue Mar 29 00:32:53 AEST 2016

The 11/70 with Mr memory had battery backup on the MOS usually so they would have the saved memory content unless they powered off the battery backup. 

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-----Original Message-----
From: Noel Chiappa <jnc at mercury.lcs.mit.edu>
To: tuhs at tuhs.org
Cc: jnc at mercury.lcs.mit.edu
Sent: Mon, 28 Mar 2016 10:18
Subject: Re: [TUHS] PDP-11/70 SPL (was: Early non-Unix filesystems?)

    > From: Dave Horsfall

    > That makes sense, and someone forgot to document it...

Or perhaps it was added precisely to get rid of the window, and then someone
discovered that it could be used to freeze the system, so they decided they'd
better not document it?

If the system had MOS memory, and you had to power cycle the machine to get it
out of this state, there wouldn't be any evidence left of who did the deed
(unless the system was writing extensive audit trailing to disk), so it would
be a great 'system assasin' (aka vandal) tool.


PS: I guess this is more PDP-11ish than UNIXish - apologies for the off-topic!

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