Hardware Detail

Item Reference:	HW0760
Machine Type:	3021	Serial Number:
	IBM 3021 Data Cell
	The 3021 data cell contains magnetic strips that are removed by the host drive for reading and writing before being replaced. The host drive was the IBM 2321 Data Cell Drive, which could hold 10 data cells with 20 sub-cells per cell. Each sub-cell had 10 magnetic strips, each containing up to 39 MBytes, so a 2321 could have on-line access to 392 MB or 784 million packed decimal digits and signs. Referring to the second picture, from the IBM archives site, in the top panel, an IBM engineer holds a magnetic tape strip on which approximately 200,000 characters of information can be stored on an IBM 2321 Data Cell Drive. Two hundred such strips were contained in a data cell and 10 interchangeable cells could be mounted in the vertical drum seen in the drive (at right). The file's positioning system rotated the drum to place a desired set of magnetic strips beneath an access station. When the drum was in position, an access device (panel at lower left) selected the proper strip from a data cell. Each strip had a coding tab which identified it among the 200 strips in the cell. In the top panel, an IBM engineer holds a magnetic tape strip on which approximately 200,000 characters of information can be stored on an IBM 2321 Data Cell Drive. Two hundred such strips were contained in a data cell and 10 interchangeable cells could be mounted in the vertical drum seen in the drive (at right). The file's positioning system rotated the drum to place a desired set of magnetic strips beneath an access station. When the drum was in position, an access device (panel at lower left) selected the proper strip from a data cell. Each strip had a coding tab which identified it among the 200 strips in the cell. The strip was then moved over a recording cylinder (panel at lower right) and past a read/write head. This device retrieved information from the strip for entry into the computer or recorded new data on the strip. The magnetic strip was then returned to its original location in the cell. The strip was then moved over a recording cylinder (panel at lower right) and past a read/write head. This device retrieved information from the strip for entry into the computer or recorded new data on the strip. The magnetic strip was then returned to its original location in the cell.
Date of Origin:		Donor:
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Location:	On Display - Corridor	Commissioned By: Museum	Until: