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Ha! Double buffering. I knew it well.

The company was Telemed and it was located near Chicago. In fact, for a while it was in an office complex a few hundred yards directly east of runway 27 R at O'hare. Often fully-laden Europe-bound 747 would take of, aiming directly overhead. We would be silently chanting "up! up!" as it felt like they were pretty close.

I don't think we did the single card trick. I do remember writing a few utilities like an editor so we could store the programs on disk instead of feeding them in each time. And a crude document processor for internal documentation. And we had a pretty serious engineering effort saving the real-time data to tape. There was always the concern about being sure that we had saved the data by the time the system signaled the hospital technician that it was done so they could unhook the patient.

The extracurricular activity I spent the most time on was porting the XPL compiler from one done at University of Washington to run on our particular configuration. Involved converting from a 7-track tape to a 9-track tape, regenerating the operating system to reduce the start address of user programs, and a few other hoops. I had read A Compiler Generator and my career was off on another track.

And we did the evening thing as well. We had two systems for redundancy, but for a while production required both machines. One would do data collection, and the other would run the diagnostic program, which spit out paper tape that was carried over to the teletypes. Since traffic was light at night, we would come in at some ungodly hour for the better part of a year doing the work to combine these systems. If a call came in, we had about an hour to get off the system so they could bring up the diagnostic system to do the analysis and generate the paper tape.

I think I remember the cards--they were binary and half full of holes, as opposed to the others (EBCDIC, i believe).



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