Univac metallic computer tape (1951)

UvA Computer Museum catalogue nr 03.47

The first electronic computer to use magnetic tapes was the Eckert & Mauchly Univac machine (1951). Magnetic tape was expected to have many advantages for information storage and processing above the usual punched cards. For instance, 'records' wouldn't be restricted to 80 characters, and tape would occupy less than 1 percent of storage volume. The quality of audio-recording tapes of the time (iron-oxide coating on paper or plastic), was not suitable for storing digital data. The Univac tape was therefore made of phosphor bronze with a cobalt-nickel plating. (Another reason may be that the use of metallic tape for digital data storage already had been investigated before and during the Second World War [1]; audiotape technology - technically rather different and less demanding as to tape quality - was imported from Germany after the war).

Tape was exclusively used on the Univac, until the computer-grade polyester tape was developed by 3M Corporation, under the supervision of IBM [2]. The first IBM tapedrives were sold in 1952. 'Magtapes' - still a half inch wide and on similar reels as the Univac metal tape - were universally adopted in the computer industry, also by Remington Rand, which in the mean time had acquired the Eckert & Mauchly company. Magtape would be the standard of industry until the late 1990's.

Notice that, in the early electronic computers, magnetic tapes were used where we would use a hard disk today. After the advent of high-capacity rotating magnetic memory devices, magnetic tapes were only used for back-up and long-term data storage.

The picture of the tape was taken from a 1983 Remington-Rand / Univac folder. Evidently, the metal-tape drives were not immediately abolished though (or because) they were not suitable for processing the new IBM-style plastic tapes.

[1] Fundamentals of digital magnetic-tape drives, Sperry-Rand Corporation 1966.
[2] IBM's Early Computers, MIT Press 1986.

This tape was donated by the Koninklijke Bibliotheek, The Hague.