IBM 305/355 Selector Assembly, RAMAC
date: label: date made
content: ca 1956
name: label: maker
content: IBM
label: maker
content: IBM
notes: label: Description
content: In the 1950s, IBM introduced a random access memory for information stored on discs in its IBM 650 and IBM 305 RAMAC computers. The RAM consisted of fifty discs mounted on a vertical shaft, each disc coated with magnetic material on both sides. The disks turned continuously at 1200 rpm. Reading and writing of information of data on the surface of the discs was performed by ite heads mounted on access arms. These arms were mounted on vertically moveable carriages like this one (three arms were provided for each file unit), and could by moved up or down to any disc.
label: Description
content: Reference:
label: Description
content: IBM, <I>650 Data-Processing System with 355 random Access Memory and 838 Inquiry Stations, Manual of Operation: Preliminary Edition</I>, 1956, pp. 16-22.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Computers
creditLine: label: Credit Line
content: Honeywell Information Systems, Inc.
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1975.319077.14
label: accession number
content: 319077
label: catalog number
content: 319077.14
objectType: label: Object Name
content: Mainframe Component
label: Object Name
content: mainframe computer component
label: Other Terms
content: Mainframe Component; Disk Storage Unit
physicalDescription: label: Physical Description
content: paper (overall material)
label: Measurements
content: overall: 42 cm x 101 cm x 30 cm; 16 9/16 in x 39 3/4 in x 11 13/16 in
label: Measurements
content: overall: 37 3/4 in x 17 in x 15 1/4 in; 95.885 cm x 43.18 cm x 38.735 cm