How Does a Cassette Tape Work?
A cassette tape, patented in 1964, is comprised of two spools and a long piece of tape, two rollers, and outer plastic shell with holes and cutouts that hook the cassette into the tape recorder’s drive. There is also a small felt pad that acts as a backstop for the record/playback head in the recorder. In a 90-minute cassette, the tape is 443 feet long. The tape inside the cassette has a thin plastic base with a coating of ferric oxide powder. The oxide is a ferromagnetic material, meaning that when you expose it to a magnetic field it is permanently magnetized. This gives cassette tapes the features that has made them so popular — you can record instantly and playback your recording any time, and you can erase and tape over previous recordings any time you like.
