The First Removable Disks
IBM introduced the first hard drive with removable disks--the IBM 1311 (shown here in the upper right image)--in 1963. It used interchangeable disk packs, each composed of six 14-inch-diameter disks. Each disk pack stored about 2MB of data. Many 1970s-era hard drives, such as the DEC RK05 (a similar model appears in the image to the far left), accommodated disk packs, which [[xref:http://en.wikipedia.org/wiki/Minicomputer|minicomputer|Minicomputer]] companies often used for software distribution.
Photos: [[xref:http://www.computer-history.info/|Lawrence Livermore National Laboratory Technical Information Department|Lawrence Livermore National Laboratory Technical Information Department]]/IBM