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IBM 350 Disk Storage (RAMAC)

IBM 350 Disk Storage (RAMAC)

Image creditMikaël Restoux (Deep silence), CC BY 2.5
CC BY 2.5 ↗

IBM 350 Disk Storage (RAMAC)

Year
1956
Creator
Reynold B. Johnson and the IBM San Jose laboratory team
Company
IBM
Location
IBM San Jose laboratory, San Jose, California

Description

The IBM 350 was the first commercial hard disk drive, with 50 aluminum disks of 24 inches that turned on one shaft. It held approximately five million characters for the IBM 305 RAMAC computer, and the photograph shows one disk.

Importance

With random access, a business could read any record in less than one second, without a search through punched cards or tape. Rey Johnson and his team designed the drive at the laboratory that IBM opened in San Jose in 1952. Like the Ampex videotape recorder of the same year, it stored data on a magnetic surface.

Interesting fact

Some IBM executives who did not believe in the stacked-disk design called it the baloney slicer.

Sources

  1. RAMAC ↗IBM Heritage
  2. Revolution: Memory and Storage, IBM 350 RAMAC ↗Computer History Museum
  3. 1956: First commercial hard disk drive shipped ↗Computer History Museum, Storage Engine
  4. The IBM 350 RAMAC Disk File (landmark brochure) ↗American Society of Mechanical Engineers · 1984-02-27
  5. IBM 350 disk storage unit (IBM Archives product profile, archived) ↗IBM Archives