IBM 610 workstation computer 3357

A trick used by operators of a 1620 mod I (which had a console typewriter -- the correct model of which I forget, but it had the physical appearance of the IBM "Executive" models, and more to the point had an actual left-and-right moving platen) solved the problem of ensuring that the sleeping operator woke up when the computer needed attention.

The process was simple: before they terminated, or when they needed an operator action, programs would write a line to the typewriter. Before going to sleep, the operator would move the platen to the far left end of its travel (putting the printing position at the far right side of the paper) and lean a pie tin against the right side of the typewriter. When the program wrote out a line, the carriage would be returned to the far right side of its travel, knocking the pie tin to the floor and (hopefully) waking the operator.

This didn't work with a 1620 mod II because the console typewriter was a Selectric.

Or they would devise hacks to let the machine run unattended. At my PPOE we had a 1620 that was used by some researchers, with disks until after the time of this story) had a problem with needing to repebreastively read a large data file over multi-hour overnight runs.

The solution was to put the data onto paper tape (remember it?), splice the tape into an endless loop, and thread it through coat hangers hung from the ceiling tiles in strategic places. Even with a tape that might have been ~100' long it worked surprisingly well...and produced amusing double-takes on the part of visitors who would see the tape jerking its way across the ceiling.

Joe Morris