[TUHS] shutdown for pre-v7 unix

Noel Chiappa jnc at mercury.lcs.mit.edu
Thu Jul 17 05:47:51 AEST 2014

    > From: Mark Longridge <cubexyz at gmail.com>

    > I was wondering if there might be a better way to do a shutdown on
    > early unix.

Not really; I don't seem to recall our having one on the MIT V6 machine.

(We did add a 'reboot' system call so we could reboot the machine without
having to take the elevator up to the machine room [the console was on our
floor, and the reboot() call just jumped into the hardware bootstrap], but in
the source it doesn't even bother to do an update(). Well, I should't say
that: I only have the source for the kernel, which doesn't; I don't at the
moment have access to the source for the rest of the system - although I do
have some full dump tapes, once I can work out how to read them. Anyway, so
maybe the user command for rebooting the system did a sync() first.)

I suppose you could set the switch register to 173030 and send a 'kill -1 1',
which IIRC kills of all shells except the one on the console, but somehow
I doubt you're running multi-user anyway... :-)


More information about the TUHS mailing list