System360 Hardwired vs. Microcoded 387

Peter Flbutt

44PS was the "native" operating system. There was some extra-cost hardware and software that provided a slow emulator for the missing instructions (plus hardware implementations of a few of them), and this let the machine run DOS or OS slowly. My college had a 44 that was time-shared between administration and academics: It ran 44PS from noon to midnight for students and faculty, and DOS from midnight to noon so the admin folks could run their COBOL and RPG (thanks to the emulator).

The weirdest addition to the machine was an 18-- um, 1832? digital-to-analog converter, funded by the school's Conservatory of Music. We used adaptations of code developed by Max Matthews at Bell Labs to synthesize music (all right, "sound") by computing discrete samples at whatever rate was desired, and then there was this rather amazing program to stream the pre-computed values through the 18xx and drive as many as four output channels. We also played little games by hooking the outputs to oscilloscopes in various ways to generate graphics -- the images were less good than one could produce on the line printer, but were *way* cooler.

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