Many early microcomputer and home computer systems used cassette tapes as an inexpensive magnetic tape data storage system. This article lists some of the historically notable formats.
As interoperability between platforms was difficult, there was little purpose to, or effort expended on, using standardized formats. The main exception to this rule was the Kansas City standard, which was supported by most S-100 bus based computers and was later adopted by a few other vendors like the BBC Computer and MSX. It also saw use as an exchange medium in some magazines and even broadcast over the radio in Europe.