[COFF] Daisy wheel printers (was: [TUHS] The Elements Of Style: UNIX As Literature)

[Lawrence Stewart]

Speaking of the Selectric

Another old story about printers.  Back in 1974 (ish) I was an undergrad at MIT working at the Architecture Machine Group, which was the predecessor to the Media Lab.  We had a home-grown OS for the Interdata 16-bit minicomputers, whose instruction sets were very much like 16-bit IBM 360’s.

There was an IBM 2741 there for talking to the institute mainframes, and somehow I got the job of writing a device driver for it.  It was quite an adventure getting the tilt-rotate codes and so forth to fit in the 160 hex bytes available…  I recall having to chain short branches together if the condition codes were right.

The success of that made me a go-to guy for printing, unfortunately, so later it was my job to patch the line printer to print capital O after the 0 wore out*.

* A real thing, way before Dilbert got hold of it.