Magnetic tape
Magnetic tape was first used to record computer data in 1951 on the Eckert-Mauchly UNIVAC I. The system's UNISERVO I tape drive used a thin strip of one half-inch (12.65 mm) wide metal, consisting of nickel-plated bronze (called Vicalloy). Recording density was 100 characters per inch (39.37 characters/cm) on eight tracks.