IBM Announces the 737 Magnetic Core Storage Unit

photograph of IBM 737 Magnetic core storage unit

IBM 737 Magnetic core storage unit

On October 1 1954 IBM announced the availability of the 737 magnetic core storage unit, a dramatic improvement over cathode ray tube memory technology, also known as electrostatic memory. By successfully adapting pill-making machines for production, IBM greatly improved the manufacture of the tiny, “doughnut” shaped, iron oxide cores, making the magnetic cores reliable and cost effective enough to serve as the basic technology behind every computer’s main memory until the early 1970s.

Though the memory units themselves were "tiny," the way they were applied in an an IBM mainframe system was large:

"The IBM 737 was formally announced on October 1, 1954. Users of the IBM 701 Data Processing System could specify the 737 in lieu of the IBM 706 Electrostatic Storage Unit to gain the advantage of magnetic core storage, viz., the elimination of regeneration time and the reduction of processing time in many applications. For example, the 737 reduced the time needed to perform additions, including access, from 60 microseconds to 36 microseconds. This faster processing speed was especially beneficial in problems involving large amounts of logic.

"The unit was available with one capacity of 4,096 36-bit words. When the 737 replaced the IBM 706, the system's 701 Electronic Analytical Control Unit had to be altered. Customers could rent a 737 for a fee of $6,100 a month.

"The IBM 737 Magnetic Core Storage Unit also could be used with the IBM 704 and IBM 709 Data Processing Systems" (

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