Compact audio cassette: Encyclopedia II - Compact audio cassette - Applications

Compact audio cassette - Applications

Compact audio cassette - Audio

The compact cassette was originally intended for use in dictation machines. In this capacity, some later-model cassette-based dictation machines could also run the tape at half speed (15/16 IPS) as playback quality was not critical. The Compact Cassette soon became a popular medium for distributing prerecorded music—initially through Philips' record company, PolyGram. Starting in 1979, Sony's Walkman helped the format become widely used and popular. In 2005, one finds cassettes used for a variety of purposes such as journalism, oral history, meeting and interview transcripts and so on. However, they are starting to give way to compact disc and more "compact" storage media. In many countries with restrictive political systems, cassettes serve as a cheap and easily concealed means for dissidents to distribute banned political speeches to large numbers of people thus circumventing government censorship. In immigrant communities, cassettes carried by travelers have served as an important means to transmit news, messages and culture between separated family members and communities.

Compact audio cassette - Home studio

In the 1980s, Tascam introduced the Portastudio line of four and eight-track cassette recorders for home studio use, allowing amateur musicians (and some professionals) to overdub themselves easily. To increase audio quality in these recorders, the tape speed is doubled in comparison to the standard; additionally, dbx noise reduction provides compression which yields increased dynamic range. Multi-track cassette recorders with built-in mixer and signal routing features provide a wide range of features and benefits from easy-to-use beginner units up to professional level recording systems.

Compact audio cassette - Home dubbing

Most cassettes were sold blank and used for recording (dubbing) the owner's records (as backup or to make compilations), their friends' records or music from the radio. This practice was condemned by the music industry with such slogans as " Home taping is killing music". However, many claimed that the medium was ideal for spreading new music and would increase sales, and strongly defended at least their right to copy their own records onto tape. In 1979 Sony brought out the Walkman, a small portable cassette player which greatly increased the popularity of listening to music on the go. Cassettes were also a boon to people wishing to make bootlegs (unauthorized concert recordings) for sale or trade, a practice tacitly or overtly encouraged by many bands with a more counterculture bent such as the Grateful Dead.

Various legal cases arose surrounding the dubbing of cassettes. In the UK, in the case of CBS Songs vs Amstrad (1988), the House of Lords found in favour of Amstrad that producing equipment that facilitated the dubbing of cassettes, in this case a twin cassette deck that allowed one cassette to be copied directly onto another, did not constitute the infringement of copyright.

Compact audio cassette - Data recording

Many early home computers of the 1970s and early 1980s, notably the TRS-80, Commodore PET, VIC-20, Commodore 64, TI-99/4a, ZX Spectrum, Amstrad CPC, Coleco Adam, Apple, and BBC Micro, could use cassettes as a cheap alternative to floppy disks as a storage medium for programs and data. Even the first version of the IBM PC had a cassette port and a command in its BASIC programming language to use it, though this was seldom used since disk drives were commonplace by this time. The typical encoding method was simple FSK which resulted typical data rates 500 to 2000 bit/s, although some games used special faster loading routines, up to around 4000 bit/s. A rate of 2000 bit/s equates to a capacity of around 660 kilobytes per side of a 90 minute tape.

The usage of both audio channels, better modulation techniques like QPSK or those used in modern modems, combined with the greater bandwidth and Signal to noise ratio of cassette tapes compared to a PSTN telephone line could have been used for achieving much greater capacities and speeds (several kBytes/s for data rate, and several MBytes on each cassette), but such a solution wasn't adopted since it would require much more expensive decoding/encoding circuitry on the computers or on dedicated "datacorders", apart from good quality tapes and recorders with constant performance.

Adapted from the Wikipedia article "Applications", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki