Turning up their noses at modern handheld devices, British researchers are rebuilding a 60-year-old, room-size computer that used 5-foot-long tubes of mercury as memory.
The Electronic Delay Storage Automatic Calculator (EDSAC) was first built at Cambridge University. It's recognized as the world's first practical electronic stored-program computer, and unlike earlier program-controlled computers, none of its wiring or switches had to be changed to perform a new calculation.
Programs were fed into the machine on a punched tape. The first was run on May 6, 1949, computing a set of square numbers.
As a general-purpose research tool, EDSAC was used by many university scientists, and helped two researchers, John Kendrew and Max Perutz, win a Nobel Prize in chemistry in 1962. It was also used in Cambridge's first computer science course, which began in 1953.
Running 650 instructions per second, EDSAC had more than 3,000 vacuum tubes arranged on 12 racks, but only a few of the original parts remain. Due to safety restrictions, the mercury delay lines that served as the machine's memory will not be reconstructed.
The Computer Conservation Society (CCS) is leading the three-year rebuild, which is expected to cost some $350,000. Visitors to the National Museum of Computing at Bletchley Park will be able to watch as the machine is built in a 215 square-foot space. The museum also houses a rebuilt Colossus, the world's first programmable electronic computer.