Where does this come from, and can I check it?

The IBM 350 disk storage unit used fifty magnetic platters each measuring twenty inches across. The figure is taken from IBM Archives, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

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Yes. It sits on the Technology shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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Mondo Knows Facts

The first commercial hard disk stored five megabytes of data

The IBM 350 disk storage unit used fifty magnetic platters each measuring twenty inches across

Introduced in 1956 with the IBM 305 RAMAC system, the IBM 350 was the size of two large refrigerators and weighed over one tonne. It stored roughly five megabytes of data on fifty magnetic aluminium disks rotating at 1,200 revolutions per minute. Data was read and written using two moving access arms.

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Where this comes from

IBM Archives

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Tags: ibm, storage, hard-disk

The first commercial hard disk stored five megabytes of data: the short answers

Where does this come from, and can I check it?: The IBM 350 disk storage unit used fifty magnetic platters each measuring twenty inches across. The figure is taken from IBM Archives, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a technology fact?: Yes. It sits on the Technology shelf, one of 1,090 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.