page_title: Kansas City standard
hierarchical_section_title: Kansas City standard
caption_attribution_description: English: The Southwest Technical Products Corporation (SWTPC) AC-30 tape interface for early personal computers was introduced in May 1976 for $80. Shown with a Sankyo ST-30 cassette recorder, a SWTPC 8K BASIC tape and a TSC 6800 Assembler tape. When the first home computers were introduced in 1975, floppy disk systems cost $2000. Storing data on audio cassettes was the low-cost but slow option that most hobbyists used. SWTPC designed their AC-30 Cassette Interface to meet the proposed "Kansas City Standard" data format. The binary data was recorded using 1200 Hz and 2400 Hz at a 300 baud data rate. At 30 bytes per second it took over 4 minutes to load an 8K file. Photo taken with a Nikon E3200 camera using tungsten lighting by Michael Holley in September 2005.
context_page_description: The Kansas City standard, or Byte standard, is a way of storing digital data on standard Compact Audio Cassettes at data rates of 300 to 2400 bits per second that was first defined in 1976. It originated in a symposium sponsored by Byte magazine in November 1975 in Kansas City, Missouri to develop a standard for storage of digital microcomputer data on inexpensive consumer quality cassettes.
  One variation on the basic standard was CUTS, which was identical at 300 bit/s, but had an optional 1200 bit/s mode as well. CUTS was the default encoding used by several machine families, including those from Acorn and the MSX. The latter added an even higher 2400 bit/s mode that was otherwise similar. CUTS' 1200 bit/s mode was also the standard used for cross-platform BASICODE distribution.
  Although the KCS standard existed from the earliest days of the microcomputer revolution, it failed to prevent a proliferation of alternative encodings. Most home computers of the era used their own formats that were incompatible with KCS or each other.
context_section_description: The Kansas City standard (KCS), or  Byte standard, is a way of storing digital data on standard Compact Audio Cassettes at data rates of 300 to 2400 bits per second (at 300–2400 baud) that was first defined in 1976. It originated in a symposium sponsored by Byte magazine in November 1975 in Kansas City, Missouri to develop a standard for storage of digital microcomputer data on inexpensive consumer quality cassettes.
  One variation on the basic standard was CUTS, which was identical at 300 bit/s, but had an optional 1200 bit/s mode as well. CUTS was  the default encoding used by several machine families, including those from Acorn and the MSX. The latter added an even higher 2400 bit/s mode that was otherwise similar. CUTS' 1200 bit/s mode was also the standard used for cross-platform BASICODE distribution.
  Although the KCS standard existed from the earliest days of the microcomputer revolution, it failed to prevent a proliferation of alternative encodings. Most home computers of the era used their own formats that were incompatible with KCS or each other.
caption: The SWTPC AC-30 Cassette Interface implemented the Kansas City standard. It sold for $80 in May 1976.
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