Remembering IBM's first mainframe, the 701

IBM's new zEnterprise EC12 mainframe boasts a power boost compared to the z196, the machine it replaces. System-wise, the EC12 features a 5.5-GHz, six-core processor, 101 cores (vs. 80 on the current z196), 161 capacity settings (vs. 125 on z196), 3T of memory and a radiator-based air-cooled system.

Maybe that's not a giant leap in processing power over its predecessor, but it is practically a new species compared with IBM's original mainframe.

IBM announced the delivery of its first mainframe on March 27, 1953: the 701 Data Processing System, of which 19 would be built that year, all of them destined for government agencies or defense industries. IBM 701 mainframe

"The calculators," IBM said, would rent for $11,900/month, which would get customers a machine that can perform "more than 16,000 addition or subtraction operations a second, and more than 2,000 multiplication or division operations a second."

Unlike its predecessor, the Selective Sequence Electronic Calculator, the 701 was not built into the room that housed it and took advantage of "all three of the most advanced electronic storage, or memory devices -- cathode ray tubes, magnetic drums and magnetic tapes."

Components of the 701 included: an electronic analytical control unit, an electrostatic storage unit, a punched card reader, an alphabetical printer, a punched card recorder, two magnetic tape readers and recorders, (each including two magnetic tapes), a magnetic drum reader and recorder and units governing power supply and distribution.

Of the 19 701s built, several were installed in government laboratories to speed calculations. At the National Oceanic and Atmospheric Administration, the Joint Numerical Weather Prediction Unit installed an IBM 701 computer in March 1955 to produce operational numerical weather prediction.  At the Lawrence Livermore National Laboratory, the arrival of an IBM 701 in 1954 meant that scientists could run nuclear explosives computations much faster.

For more big iron, visit IBM's mainframes photo album.

IBM 701 mainframe

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