🎄💾🗓️ Day 11: Retrocomputing Advent Calendar - The SEL 840A🎄💾🗓️
Systems Engineering Laboratories (SEL) introduced the SEL 840A in 1965. This is a deep cut folks, buckle in. It was designed as a high-performance, 24-bit general-purpose digital computer, particularly well-suited for scientific and industrial real-time applications.
https://en.wikipedia.org/wiki/Systems_Engineering_Laboratories
Notable for using silicon monolithic integrated circuits and a modular architecture. Supported advanced computation with features like concurrent floating-point arithmetic via an optional Extended Arithmetic Unit (EAU), which allowed independent arithmetic processing in single or double precision. With a core memory cycle time of 1.75 microseconds and a capacity of up to 32,768 directly addressable words, the SEL 840A had impressive computational speed and versatility for its time.
The first "personal" computers I used were Xerox Alto, Xerox Dorado, Xerox Dandelion (Xerox Star 8010), Apple Lisa, and Apple Mac, and an original IBM PC. Later I used DEC VAXstations.
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Dan kinda wins the first computer contest if there was one... Have first computer memories? Post’em up in the comments, or post yours on socialz’ and tag them #firstcomputer #retrocomputing – See you back here tomorrow!
@adafruit Here's my first computer, a Motorola 6800 evaluation board. It was maxed out with 768B of RAM. I'd write my programs in assembler, hand assemble them, wrap them in S-records, and key them in on a teletype (hooked up to a serial port connected by a 1/4" stereo plug). I still have it, it still works (but now sports 16kB of RAM. #firstcomputer #retrocomputing
