The Compact Cassette is a plastic case containing a spool of 3.81 mm magnetic tape spooled between two reels. The tape is run at a rate of 4.76 cm/second. A tape head in the tape player or deck, in contact with an exposed portion of the tape, interprets an analog signal from the tape's magnetic surface.
The Compact Cassette is essentially a self-contained reel-to-reel system using a narrow strip of tape and enclosing both reels within the plastic housing. When it first came into market, the storage capacity and sound quality of audio encoded on cassette tapes was quite poor due to its small size, but developments in analog encoding resulted in great improvements over the life of the technology.
The Compact Cassette was introduced as a brand name product by Dutch electronics firm Philips. Through 1963 and 1964, Philips rolled out the cassette tape as a sound recording medium for its North American and European markets. The Compact Cassette was initially marketed as a medium for recording personal dictation, but early improvements in the audio quality led makers to believe that the cassette was a viable alternative to vinyl records. Philips licensed its Compact Cassette to other electronics firms free of charge, and the popularity of the cassette began to take off.
In 1971, a new process for using chromium dioxide on the surface of the tape was discovered. The resulting leap in quality led to the cassette becoming a new standard for the recording industry.
In the 1980s, Sony began marketing its portable cassette player, the Walkman, worldwide. This led to an explosion in the popularity of the cassette. Car radios featuring cassette tape decks became standard, supplanting the short-lived 8-track. Cassette tapes became the standard for home audio, and vinyl records quickly disappeared from the shelves of music sellers.
Besides serving as a recording medium for audio, the Compact Cassette had a number of other applications. Because a single tape could be re-recorded many times, it became the medium of choice in early telephone answering machines. Cassettes were also produced that could be run on a continuous loop, thus making them ideal for commercial applications such as the music played over speakers in retail stores.
Some early desktop computer makers used the cassette tape as a storage medium for data. Apple and Hewlett Packard each offered computers with built-in tape drives.
The Compact Cassette remained popular until digital technology made advances in the 1990s. Home computers with hard drives (as well as CD-ROM drives and floppy discs) made the tape's data storage use unnecessary.
The Compact Disc, which had been in production since 1982, finally became inexpensive enough to compete directly with cassettes. Its larger capacity and the ability to make digital copies without any loss of quality led consumers to embrace the CD, leaving the Compact Cassette behind as an obsolete technology.