A so-called mini-reel was common for smaller data sets, such as for software distribution. Most tape drives could support a maximum reel size of 10.5 inches (267 mm). During the 1980s, longer tape lengths such as 3,600 feet (1,100 m) became available using a much thinner PET film. Different tape lengths were available with 1,200 feet (370 m) and 2,400 feet (730 m) on mil and one half thickness being somewhat standard. Magnetic tape dimensions were 0.5-inch (12.7 mm) wide and wound on removable reels. IBM's technology soon became the de facto industry standard. IBM computers from the 1950s used ferric oxide coated tape similar to that used in audio recording. IBM formats ġ0 + 1⁄ 2-inch (270 mm) diameter reel of 9-track tape A small reel of mylar tape provided separation from the metal tape and the read/write head. Making allowances for the empty space between tape blocks, the actual transfer rate was around 7,200 characters per second. Of the eight tracks, six were data, one was for parity, and one was a clock, or timing track. Recording density was 128 characters per inch (198 micrometre/character) on eight tracks at a linear speed of 100 in/s (2.54 m/s), yielding a data rate of 12,800 characters per second. The UNISERVO drive recording medium was a thin metal strip of 0.5-inch (12.7 mm) wide nickel-plated phosphor bronze. Magnetic tape was first used to record computer data in 1951 on the UNIVAC I. yet it stored up to 20 percent more data,' large computer systems started to move away from open reel tapes and towards cartridges. With the introduction of the IBM 3480 cartridge in 1984, described as Tape cartridges and cassettes were available starting in the mid-1970s and were frequently used with small computer systems. This standard for large computer systems persisted through the late 1980s, with steadily increasing capacity due to thinner substrates and changes in encoding. Initially, magnetic tape for data storage was wound on 10.5-inch (27 cm) reels. 3.9 Cartridge memory and self-identification.

Record cassette tapes to computer