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Date: Wed, 27 Aug 1997 11:16:33 -0700 (PDT)
Organization: Atlas Telecom
From: Simon Shapiro <Shimon@i-Connect.Net>
To: pechter@lakewood.com
Subject: Re: ? power outages and file system corruption
Cc: hackers@freebsd.org
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Hi Bill Pechter;  On 27-Aug-97 you wrote: 

...

>  Nah, time of day clock battery backup was standard on 11/780's
>  Memory battery backup was an option on both.  Neither one were nvram.
>  Neither one avoided disk checks on power fail (VMS mount verification).
>  The batteries needed to be checked occasionally and replaced if they
>  were bad.

Ah, so technology yet advanced :-)  We had  a battery and now it is gone.
You are probably right about it being an option.  More proof things are
still the same.

>  
>  VAX/VMS, however did great powerfail recovery.  I dropped the power to
>  an
>  entire computer room at Fort Monmouth as a test.
>  
>  The 6 RP06's and 2 RM05's spun down, the cpu fans went quiet.  The
>  VT100's
>  froze and blinked out.  I waited 5 minutes and flipped the main circuit
>  breaker on.  The machine reloaded the console firmware, checked the
>  memory 
>  status, and resumed execution of empire (or some other game which was
>  the
>  VAX/VMS rogue equivalent on all terminals) at the next move.

I had this excercise done on production units twice.  Once by a truck which
backed up into a 6Kv line dropping it to the ground.  Another by a fire in
an ajacent wherehouse.

>  Unix would do the same thing based on the memory register status being
>  ok.

Would maybe.  System V rlelease from the Labs did not.  Niether did BSD, or
we will have this code in FreeBSD.  No?

You are right of course about RSTS.  That was on PDP-11, which had a
battery 
support for main memory too, I think.  Had great lead bars at the bottom of
the cabinet too.  I melted down the last one about a year ago.

Simon