RAMAC: 5 MB circa 1956

Steve Wozniak’s 9 Favorite Gadgets


It looks like a giant air purifier, but the contraption shown here was the heart of the world's first disk drive. It contains 50 24-inch disks stacked parallel, spinning at 1,200 rpm. It can hold 5 megabytes of information. The disk stack was made in San Jose, Steve Wozniak's hometown.

Comment: Wiki article here


The IBM 350 disk system stored 5 million 8-bit (7-bits plus 1 odd parity bit) characters. It had fifty 24-inch-diameter (610 mm) disks. Two independent access arms moved up and down to select a disk, and in and out to select a recording track, all under servo control. Average time to locate a single record was 600 milliseconds.


Currie Munce, research vice president for Hitachi Global Storage Technologies (which has acquired IBM's hard disk drive business), stated in a Wall Street Journal interview that the RAMAC unit weighed over a ton, had to be moved around with forklifts, and was delivered via large cargo airplanes. According to Munce, the storage capacity of the drive could have been increased beyond five megabytes, but IBM's marketing department at that time was against a larger capacity drive, because they didn't know how to sell a product with more storage.

Final comment: Last week I bought an 8 gig SD card for my camera for about $ 15.

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