Reverse engineering the Mitra 125 MS: The French-built minicomputer that controlled Spacelab
By
elpocko
Fresh out the oven, still warm. Top of the tray.
Summary
This article details the reverse engineering of a processor board from the Mitra 125 MS minicomputer, which was used to control the Spacelab laboratory aboard the Space Shuttle in the 1980s. Unlike modern computers, this 16-bit French-built computer had no microprocessor chip; its processor was constructed from multiple boards of discrete chips. The author focuses on one specific board that is part of the computer's Arithmetic/Logic Unit (ALU), explaining its circuitry and architecture.
Key quotes
· 4 pulledSpacelab was a reusable laboratory that could be carried in the cargo bay of the Space Shuttle, providing lab space for astronauts and experiments.
Unlike modern computers, this computer didn't contain a microprocessor chip.
Instead, its 16-bit processor was constructed from several boards of chips.
In this article, I reverse-engineer one of the processor boards, shown below, part of the computer's Arithmetic/Logic Unit (ALU).
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