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KF5JRV > TECHNI 02.11.25 11:03z 31 Lines 3124 Bytes #30 (0) @ WW
BID : 15072_KF5JRV
Subj: Ferranti Mark 1
Path: SR8BBS<OK0NBR<OK2PEN<CX2SA<PI8ZTM<PA8F<VE3CGR<VE3QBZ<VE2PKT<PY2BIL<
K5DAT<KF5JRV
Sent: 251102/0941Z 15072@KF5JRV.#NWAR.AR.USA.NA BPQ6.0.24
Ferranti Mark 1
The world's first commercially available general-purpose electronic computer, produced by Ferranti. The first machine was delivered to the University of Manchester in February 1951. Ferranti Mark 1 was a tidied up and commercialized version of the Manchester Mark 1 developed in 1948-1949 at the University of Manchester, which was a further development of the Manchester Small-Scale Experimental Machine (SSEM, nicked Baby) by Frederic C. Williams, Tom Kilburn and Geoff Tootill. During the 1940s, Alan Turing and others such as Konrad Zuse developed the idea of using the computer's own memory to hold both the program and data. It was John von Neumann who became widely credited with defining that stored-program computer architecture, on which the Mark 1 was based
MEMORY:
The Mark 1 used a 20-bit word stored as a single line of dots on a Williams-Kilburn tube, each tube storing 64 lines. Instructions were stored in a single word, while numbers were stored in two words (40 bits). The main memory had eight tubes, each storing one page of 64 words. Other tubes stored the single 80-bit accumulator (A), the 40-bit multiplicand/quotient register (MQ) and eight B-lines, or index registers, used to modify instructions. An extra 20-bit word per tube stored an offset value into the secondary storage, a 512-page magnetic drum
INSTRUCTIONS:
The 20 bit instructions had an address and an operator part. The coding of instructions was: bits 0-8 the CRT address, bits 10-12 the B-line address and bits 13-19 the function code. Writing of programs was based on a numerical system to the base 32. Integer numbers were usually treated as 40 bit double words, negative numbers already represented as Two's complement. The Mark 1 had an instruction to find the position of the most significant digit aka Bitscan reverse or Leading Zero Count for the purpose to convert integers to normalized floating point numbers, as well as a Population Count instruction for Cryptography purposes. Arithmetical and logical instructions other than multiplication took 1.2 milliseconds (5 x 240 microseconds beats ), 40*40=80 bit multiplication 2.16 milliseconds (9 beats)
CHECKERS:
The first successful AI program was written in 1950/1951 by Christopher Strachey, initially for the Pilot ACE at National Physical Laboratory, exhaustings its memory. Stracheyâ€Ös checkers (draughts) program was soon ported and ran on the Mark I computer at the University of Manchester, and by the summer of 1952 the program could play a complete game of checkers at a reasonable speed, and already featured Bitboards for White, Black and Kings to represent the board
CHESS:
Alan Turing, while affiliated with the University of Manchester began "porting" his pen and paper program Turochamp
to run on a Mark 1, as well started with Michie's and Wylie's program Machiavelli, but could not complete them. Influenced by Turing's ideas, Dietrich Prinz developed the first limited chess program for the Ferranti Mark 1 in 1951, dubbed Mate-in-two.
73 de Scott KF5JRV
Pmail: KF5JRV@KF5JRV.#NWAR.AR.USA.NA
Email KF5JRV@gmail.com
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