A Microcassette (often written generically as microcassette) is an audio storage medium introduced by Olympus in 1969. It uses the same width of magnetic tape as the Compact Cassette but in a much smaller container. By using thinner tape and half or a quarter the tape speed, microcassettes can offer comparable recording time to the compact cassette. The original standard microcassette, the MC60, gives 30 minutes recording per side at its standard speed of 2.4 cm/s, and double that duration at 1.2 cm/s. Unlike the Compact Cassette, a choice of recording speeds was provided on the original recorders and many others; the tape also spools in the opposite direction, from right to left. For transcription purposes, continuously variable speed was provided on many players.
Microcassettes have mostly been used for recording voice. In particular, it is commonly used in dictation machines and answering machines. However, it has also been used as a medium for computer data storage, and as a medium for recording music. For the latter purpose, devices for recording microcassettes in stereo were produced in 1982 and, for higher fidelity, microcassettes using metal tape were sold. This was an attempt by Olympus to cash in on the burgeoning Walkman market, but the limited fidelity and high price of the equipment meant that these units were phased out within 24 months. One model, the Olympus SR-11 even had a built-in FM tuner, and a stereo tie-clip microphone was sold as an accessory for it, which was popular with concert-goers who would record the concerts.
Comparable products to the microcassette include the minicassette, produced by Philips, and the picocassette, produced by Dictaphone. Of the three formats, the microcassette was the most common. In 1992, Sony released the NT memo recording system which employs a small cassette, but records digitally.