FYI -- The Guardian doesn't usually screw up scientific/technical/mathematical things, but mathematically mature babies are rolling their eyes... Perhaps it was 2^18-1 ? 2^18+1 ? BTW, if the total instruction store only holds 32 instructions, how complex could the program be? How long could the longest-running program that *halts* run (in terms of program steps) ? https://www.theguardian.com/global/2017/nov/08/geoff-tootill-obituary Geoff Tootill obituary Computer engineer who developed 'Baby', the world's first stored-program computer Martin Campbell-Kelly Wednesday 8 November 2017 15.53 GMT ... In order to test the memory when it was constructed, Kilburn and Tootill designed an elementary computer, officially known as the Small-Scale Experimental Machine, but better known as "Baby". The computer could store just 32 instructions or numbers using a single cathode ray tube. The machine first worked in June 1948, taking 52 minutes to find the highest factor of 2^18, involving about 3.5m arithmetic operations. ---- Even less forgivable, *SlashDot* also screwed this one up: https://hardware.slashdot.org/story/17/11/26/197221/computer-pioneer-geoff-t...