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SSEM Controls

Click CRT bits to toggle (0/1)
Instructions: JMP, JRP, LDN,
STO, SUB, CMP, STP
CI: 0 (line)
PI: 0 (instruction)
ACC: 0
Phase: IDLE

Manchester Baby (SSEM)

1948 — University of Manchester

The Small-Scale Experimental Machine was the world's first stored-program computer. Built by Frederic Williams, Tom Kilburn, and Geoff Tootill, it stored both programs and data on a Williams tube CRT display.

Memory: 32 words of 32 bits each, displayed as bright/dark dots on a cathode ray tube. On June 21, 1948, it ran its first program: finding the highest proper factor of a number.

Only 7 instructions. The birth of software.