Thursday, December 16, 2010

Cold today

We have some icy winter weather today, so I'm working from home.  Some people came in to the office and they're reporting that it's significantly cooler than usual, which reminds me of this story:

I was in high school, working on a PDP-11/44.  It was about the same temp outside that day as it is now - 20-30°F (-7 to -1°C), perhaps a little colder than today.  The PDP wouldn't tolerate temperatures over about 75°F (24°C), above which any job running was subject to terminate with the dreaded "ODD ADDRESS OR OTHER TRAP FOUR" message after a few seconds of execution.  So that day, the air conditioner froze over, and the program was due at the end of the day.  We set up two box fans blowing outside air into the terminal room and blowing terminal room air into the PDP room.  I sat in the terminal room (of course), gloves off so I could type, wearing a coat, scarf, and hat.  Brrr...

I think to post it here because a search for "ODD ADDRESS OR OTHER TRAP FOUR" turns up a bunch of flummoxed people, but nobody mentions checking the thermostat.  From my experience, that message always came when the computer was overheated. 

1 comment:

Mike said...

Ah, the PDP. Such a lovely, temperamental machine.