Kansas City standard

The Kansas City standard (KCS), or Byte standard, is a data storage protocol for standard cassette tapes or other audio recording media at 300 bits per second. It originated in a symposium sponsored by Byte magazine in November 1975 in Kansas City, Missouri, to develop a standard for the storage of digital microcomputer data on inexpensive consumer quality cassettes. The first systems based on the standard appeared in 1976.

One variation on the basic standard is CUTS, which is identical at 300 bit/s, but with an optional 1200 bit/s mode. CUTS is the default encoding used by several later machine families, including those from Acorn and the MSX. MSX added a higher 2400 bit/s mode that is otherwise similar. The 1200 bit/s mode of CUTS was used as the standard for cross-platform BASICODE distribution.

KCS originated from the earliest days of the microcomputer revolution, among other prolific protocols. Most home computers of the era have unique formats without any intercompatibility.