Cassette tape

The Compact Cassette or Musicassette (MC), also commonly called the tape cassette, cassette tape, audio cassette, or simply cassette, is an analog magnetic tape recording format developed by a team led by Lou Ottens at Royal Philips in Hasselt, Belgium. It was introduced in September 1963 for audio recording and playback. It was also a popular data storage medium for early microcomputers. Compact Cassettes can be obtained with existing content as a pre-recorded cassette, or as a fully-recordable "blank" cassette. Both forms are reversible by the user.

Specifications
Compact Cassettes contain two miniature spools, between which the magnetically coated, polyester-type plastic film (magnetic tape) is passed and wound. These spools and their attendant parts are held inside a protective plastic shell which is 4 by 2.5 by 0.5 inches (10 cm × 6.3 cm × 1.3 cm) at its largest dimensions. The tape itself is commonly referred to as "eighth-inch" tape, supposedly 1⁄8 inch (3.17 mm) wide, but it is slightly larger: 0.15 inches (3.81 mm). Two stereo pairs of tracks (four total) or two monaural audio tracks are available on the tape; one stereo pair or one monophonic track is played or recorded when the tape is moving in one direction and the second (pair) when moving in the other direction. This reversal is achieved either by flipping the cassette, or by the reversal of tape movement ("auto-reverse") when the mechanism detects that the tape has come to an end.

History
Compact cassette technology was originally designed for dictation machines, but improvements in fidelity led to it supplanting stereo 8-track cartridges and reel-to-reel tape recordings in most non-professional applications. Its uses ranged from portable audio to home recording. The first monaural cassette player designed for use in car dashboards was introduced in 1968. From the early 1970s to the mid-2000s, the cassette was one of the two most common formats for prerecorded music, first alongside the LP record and later the compact disc (CD).

Data recording
In November 1975, Byte magazine held a symposium in Kansas City, Missouri to establish a standardized method of recording data from microcomputers onto readily available audiocassettes. Data was modulated (like a modem) into an audio signal that could be transmitted to the tape recorder. This method became the Kansas City standard, also called the Byte standard, which initially operated at 300 baud, with faster rates being implemented later.

Microsoft
The first line of products from Microsoft (then known as "Micro-Soft") started with its own implementation of BASIC, adapted by Bill Gates and Paul Allen for the Altair 8800 in 1975. It was made available on paper tape, or cassette tape for systems that had such an interface. Microsoft licensed its BASIC to run on early home computers, including the Apple II Plus, Commodore 128, and TRS-80, which all supported cassette tape storage at the time. Cassette tapes were eventually replaced by faster floppy disks as the dominant form of data storage for personal computers.