1958 · Transistorized Computer · Work 833 of 1,871
An institute room of a technical university in Vienna in spring, a long wall of light grey steel cabinets with their doors open, inside them row upon row of red-brown circuit boards standing on edge, each carrying small black glass-cylinder transistors, resistors with coloured rings and small black ring cores wound with red wire, a man in a grey work coat seen from behind drawing one board halfway out, a second hand holding an oscilloscope probe to it, in front a wooden table with a soldering iron and a spool of wire, tall double windows with spring light from the left, a parquet floor.
What it was used for
The transistor computer was built at the Vienna Technical University from 1956 by Heinz Zemanek with Kurt Bandat, Rudolf Bodo, Viktor Kudielka, Eugen Mühldorf and Kurt Walk, and completed in May 1958. It used 48-bit words at a 132 kHz clock, multiplied two ten-digit numbers in 26 ms and drew about 400 watts. Internal storage was a 50-word core memory, external storage a magnetic drum holding 10,000 words. On 27 May 1958 it determined the prime number 5073548261 in 66 minutes; it also played twelve-tone series through a coupled frequency generator. From 1961 to 1966 it stood in the IBM laboratory in Vienna, which Zemanek was allowed to set up after the machine's success. It now belongs to the Technisches Museum Wien.
What was new
What marked the machine out was the absence of valves: about 3,000 transistors and 5,000 germanium diodes, plus 15,000 resistors, 5,000 capacitors, 20 km of wiring and some 100,000 soldered joints - on only 400 watts. Philips gave Zemanek the transistors as a gift; the type had been developed for hearing aids, not for arithmetic units. With its 48-bit words, up to 80,000 different machine instructions were possible in programming. The name was chosen as a counterpart to the American machine names "Whirlwind" and "Taifun" - a Mailüfterl is a light May breeze.
What the sources leave open: The Technisches Museum Wien and TU Wien both give about 3,000 transistors. The prime 5073548261 and the 66 minutes appear only in the museum record; TU Wien speaks generally of calculating primes. Neither source says the Philips transistors were rejects - TU Wien calls them a gift. Neither source calls the machine the first transistor computer.
Connections
Every connection names its kind. “Forerunner” on its own would be a claim.