Comment by gregjor | Hacker News Reader

Comment by gregjor | Hacker News Reader

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I worked with mainframes and superminis back in the 70s. My first job was night computer operator.

Computer operator: scheduling and monitoring jobs, managing the print spool (queue) printing reports, stripping (removing carbon paper) and collating, sometimes swapping disk packs, loading/unloading tapes, running backups. And making sure the computer didn’t crash or halt. The minis and mainframes I worked on generally ran one job at a time, and the jobs might have a sequence, reading from and writing to disk or tape.

We kept transistor radios on top of the computer cabinets. Each job made a distinctive sound, as did runaway programs (infinite loops, for example). A halted computer did not make a sound so the radio was an early warning that something wasn’t right.

Tape librarian: magnetic tapes degrade over time from use, stretching, humidity. The tape librarian cataloged the contents and sequence of tapes, how many times they were used, their age. When a tape had too many errors or got to end of life the tape librarian would schedule a duplicate job.

I remember something that happened fairly often. The nightly jobs were on a schedule with estimated run time and special instructions. The jobs came with disk files or sometimes written job control language (JCL) that specified environment variables, required disk packs, resource requirements (temp disk space, memory, tapes). The JCL language was terse and arcane and the programmers and managers who submitted jobs sometimes messed it up. I would have to correct that and sometimes write the JCL if the job didn’t come with a file, or the instructions said “Same JCL as last run.”

Mostly the job was rote and I could tape boxes of paper together end to end and sleep while everything churned away. The most exciting night was a meltdown. I could do my Friday shift anytime over the weekend. I went in on Saturday afternoon and found the computer room very hot. The AC had failed and the backup AC didn’t switch on. The computer room and tape vault were climate-controlled. I could hear one of the disk drives (the size of a small refrigerator) whining. I ran around shutting everything down, but one of the GE disk drives had overheated and the disk platters had melted. Most of the drives were HP and they survived, but the cheaper GE drives were all damaged. The AC supplier’s insurance had to pay for the damage.

It’s hard to imagine today how big, slow, expensive, and delicate computers were back then. Hardware failures were common. RAM was measured in kB or low mB. Disk storage was expensive and slow.

The job I’m describing was for a school district. They had two HP 3000 superminis (16 bit), two HP 2000 timesharing systems, and an IBM S/370. The HPs were identical, we could use one as a hot spare if necessary, though back then HP stood for rock-solid reliability. The HP 3000 has a long history, I wouldn’t be surprised to find some still in use, and I know there are emulators for it to run old application code (COBOL, Fortran, Basic). The HP 2000 systems were common timesharing systems used in public schools for admin work and student accounts for learning programming. My first exposure to programming was HP 2000 timeshared BASIC on a teletype model 33 in my high school.

After the school district I got a job as a junior programmer at Blue Ribbon Sports, now known as Nike. They had several DEC PDP-11s and two DECSystem 20 superminis, all in a secure climate-controlled rooms. The programmers did not have access to the computer room, we didn’t have admin (“wheel”) accounts. We had to ask the operators to do system admin things for us. I had an ADM-3a terminal at home with an acoustic coupler, then Nike let me take a VT-100 terminal home so I could work more. We had remote work way back then in 1979.

> We kept transistor radios on top of the computer cabinets. Each job made a distinctive sound, as did runaway programs (infinite loops, for example). A halted computer did not make a sound so the radio was an early warning that something wasn’t right.

You mean you used the radio like a baby monitor?

The different components would make different electromagnetic interference patterns. You could tell what the computer was doing (or not doing) from the static.

This is also how some of the first computer generated music was produced.

I remember listening to my TRS-80 that way -- easy to monitor outer/inner loops, different sounds for Basic vs. asm code, etc. The downside was that often people had no choice -- the TRS-80 was so noisy, that nobody in the house could watch (OTA broadcast) TV if I had the computer on.

Can confirm. I did some work on a TRS-80 in a Radio Shack store (inventory on cassette tapes!). The “trash 80” as it was called would interfere with the stereo equipment in the store, the manager would have to turn the little computer on the counter off to demo a receiver.

> "trash 80" Boo! :)

Still much love for it...

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