 This de facto standard for large computer systems persisted through the late 1980s, with steadily increasing capacity due to thinner substrates and changes in encoding.Tape cartridges and cassettes were available starting in the mid-1970s and were frequently used with small computer systems.With the introduction of the IBM 3480 cartridge in 1984, described as 
"about one-fourth the size ... yet it stored up to 20 percent more data," large computer systems started to move away from open reel tapes and towards cartridges.