(sch) It was once the absolute heavyweight among the early computers: ERMETH, the “ETH Electronic Calculating Machine”. Its heart, the main memory shaped like an old washing machine drum, weighs 1.5 tons just on its own. Its 1,500 thermionic valves fill ten massive metal cabinets and the unwieldy control panel is like a Hammond organ with a keyboard and drawbars. Constructed in 1957, ERMETH is the oldest computer built by ETH Zurich.

On Wednesday 29 November 2006 Carl August Zehnder, Professor Emeritus for Computer Science at ETH Zurich, handed over the historic computer to Beatrice Tobler from the Museum of Communication in Bern as a permanent loan. About 150 interested people took the opportunity to see ERMETH one last time in the basement of the Department of Computer Science. The computer has been in temporary storage in the IFW (Institute for Scientific Computing) since 2004 after having been exhibited in the Technorama for many years.

The power of a pocket calculator

Zehnder, one of its early users in the ERMETH development team at that time, looked back on the early days of computer science during his talk and recalled the computer’s vagaries: “The dreaded red lamps lit up every time the electricity supply to the city’s tram network was switched off.” ERMETH, which consumed 30 kilowatts of power, was an electricity guzzler. The memory capacity was barely 10,000 words of 14 decimal digits each. The computer received its instructions via punched cards and the results appeared on an IBM typewriter. There was still no talk of word processing, because numerical representations were all that was possible, and so the computer was used exclusively for mathematical problems. Nowadays all the functions of this monster computer, which was a milestone in its time, would fit into a handy pocket calculator.

In 1950 ETH was already the first higher education institution in the whole of continental Europe to own a programmable computer, the Z4 automatic calculator built by the German engineer Konrad Zuse. ETH did pioneering work by developing ERMETH from 1954 to 1957 and was thus able to increase its computing power by a factor of 100 compared to the predecessor model.