Data Storage Technology (DST) is a 19 mm (0.75 in) wide magnetic tape data storage format created by Ampex in 1992. The DST format was also made by Ampex as a digital videotape format, DCT, using the same design of cassette. DST is relatively high capacity and high speed, especially compared to other tape technologies available in the 1990s. There are 3 standard tape cartridges sizes compatible with each generation, "Small", "Medium", and "Large".