Greetings. Once upon a time long ago, I was sitting alone in the UCLA ARPANET site #1 computer room late one night when the high Santa Ana winds outside started disrupting power. Hit after hit, very dangerous for the minicomputers, disk drives, and other equipment in that room, since we didn't have uninterruptible power supplies back then.

I made some calls and it was decided I should shut everything in the room down. Everything. I phoned the ARPANET NOC (Network Operations Center) at BBN and explained the situation, since I was about to shut down IMP #1 (essentially, a refrigerator-sized router) on ARPANET which sat in a corner of the room, and doing this could cause disruptions if done in an unplanned manner. The IMP was *always* running -- I had never seen it powered down.

I worked my way around the room, powering down terminals and disks, and printers, and the power supplies on the 11/45 (ARPANET Host #1 - UCLA-ATS) and the 11/70 (Host #129 [1+128 on IMP #1] - UCLA-SECURITY. Back then my email addresses were LAUREN@UCLA-ATS and LAUREN@UCLA-SECURITY -- no domains yet.

The usual roar of the machines gradually got quieter and quieter, until only the IMP was left. I pulled down the power switch. Now there was dead quiet except the hum of the lights, a situation I'd never experienced in that room before. Very odd feeling.

Suddenly I heard a click -- the IMP was powering back up by itself. Damn. I pulled down the switch again. Quiet for a time, then click and it came back up yet again. Before I started thinking about screwing around with its power cables or turning off breakers that could have unexpected effects, I called the NOC again to ask them if they had any ideas.

"Oh yeah. We should have told you! There's a little switch that controls auto-restart. Surprise!"

So I found and flipped that little toggle switch, powered down the IMP again, and this time it stayed down. I had turned off the ARPANET -- at least at UCLA. -L

@lauren
What year was this? I first started tending a standalone PDP11/34 in 1976. Those were the days!

@dbc3 @lauren
But did you have to fix a wire wrapped CPU?

@EugestShirley @dbc3 Not that night. But I did use a wire wrap gun on the 11/70 in that room more than once!

@lauren @dbc3
Wow! They didn't make you do it by hand!? You were lucky,

@EugestShirley @dbc3 I brought my own wire wrap tools!

@lauren @dbc3
I only had to do it when the tech-on-call failed to show.
He had a tendency to get "snowed-in" even in Southern California.