Tuesday, October 05, 2004
Ontology in a rub-a-dub style

[E]ven if the old rootedness is being lost in this age, may not a new ground and foundation be granted again to man, a foundation and ground out of which man's nature and all his works can flourish in a new way even in the atomic age?
Sir Robert Marley:
Emancipate yourselves from mental slavery
None but ourselves can free our minds
Have no fear for atomic energy
Cause none of them can stop the time

I once worked in the control room of an atomic reactor. The engineering firm I worked for had been contracted to write an expert system to filter control room alarms. The moment the accident occurred at Three Mile Island their control panels lit up, and it took them days to trace back to the original failure through the cascades of alarms. The expert system was intended to filter and prioritize the alarms so that in the event of an accident the personnel in the control room would be directed to the central failure immediately.

The control room at Diablo Canyon was run by a, by that date, obsolete mini computer; it was too expensive to go through the regulatory process to update the control room hardware. All entire RAM in the computer was in a shared memory pool and all the alarms were at a specific memory address. I convinced a colleague at the firm who knew assembler to write a routine that would get interrupted when an alarm changed state, and send the data out a UDP port. Most computers had TCP/IP because that was a requirement from the Pentagon, the biggest buyer of computers in those days.

Listening at the other end I had a 386 running Xenix. It would get the alarm data through a socket, store it in a file, and go back to listening. Another daemon would monitor the file system. When the daemon detected a new file, it would open a socket on a second ethernet card, and send the alarm data to an expert system in a TI Explorer II Lisp machine. The first Explorer had been a workstation, but the II was now a board inside a Macintosh II.

The 386 was there to act as a buffer. Alarms might be generated faster than the expert system could process them. Garbage collection in the Lisp machine might have prevented the expert system from getting an alarm if it had been connected directly to the control room computer.

The 386 existed because we couldn't stop the time.

That's what I remember of that time. The rest is a blur of nearby hotels and restaurants, and driving back to the City up Highway 1, in the fog though Big Sur, past a dying Henry Miller's home, listening to a tape of Gil Scott-Heron's greatest hits.
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