From mboxrd@z Thu Jan 1 00:00:00 1970 From: dave at horsfall.org (Dave Horsfall) Date: Wed, 30 Sep 2020 08:24:19 +1000 (EST) Subject: [COFF] German Z4 User Manual from 1945 found In-Reply-To: References: Message-ID: On Sat, 26 Sep 2020, Rudi Blom wrote: > "Researchers will be able to gain a deeper understanding of what’s > considered the world’s oldest surviving (digital) computer after its > long-lost user manual was unearthed. The Z4, which was built in 1945, > runs on tape, takes up most of a room and needs several people to > operate it. The machine now takes residence at the Deutsches Museum in > Munich, but it hasn’t been used in quite some time." > https://www.engadget.com/oldest-computer-manual-zuse-z4-161214346.html Which reminds me of the Z3; from Wikipedia: ``The Z3 was a German electromechanical computer designed by Konrad Zuse in 1935, and completed in 1941. It was the world's first working programmable, fully automatic digital computer. The Z3 was built with 2,600 relays, implementing a 22-bit word length that operated at a clock frequency of about 4–5 Hz. Program code was stored on punched film. Initial values were entered manually. The Z3 was completed in Berlin in 1941. It was not considered vital, so it was never put into everyday operation. Based on the work of Hans Georg Küssner (cf. Küssner effect) e.g. a "Program to Compute a Complex Matrix" was written and used to solve wing flutter problems. Zuse asked the German government for funding to replace the relays with fully electronic switches, but funding was denied during World War II since such development was deemed "not war-important". The original Z3 was destroyed on 21 December 1943 during an Allied bombardment of Berlin. That Z3 was originally called V3 (Versuchsmodell 3 or Experimental Model 3) but was renamed so that it would not to be confused with Germany's V-weapons. A fully functioning replica was built in 1961 by Zuse's company, Zuse KG, which is now on permanent display at Deutsches Museum in Munich. The Z3 was demonstrated in 1998 to be, in principle, Turing-complete. However, because it lacked conditional branching, the Z3 only meets this definition by speculatively computing all possible outcomes of a calculation. Thanks to this machine and its predecessors, Konrad Zuse has often been suggested as the inventor of the computer.'' -- Dave