Magnetic Tape
Tape Data Recovery - Magnetic Tape
Magnetic tape is a medium for magnetic recording. The medium used long and narrow plastic strip coated with a magnetizable substance. All of the recording tapes available for recording computer data, audio or video signals are using magnetic tapes. The device that stores computer data on a magnetic tape is called a tape drive. Devices that record and playback audio and video using magnetic tape are generally called tape recorders and video tape recorders respectively.
Magnetic tapes surpassed gramophone records in that they allowed recording to be created in multiple stages. They also enabled easy mixing and editing with a minimal loss in quality between generations. In computing, magnetic tape allowed huge amount of data to be stored in computers for long periods of time and rapidly accessed when needed.
Audio Recording
Magnetic tape for recording sound was first invented by Fritz Pfleumer in 1928 in Germany. This method used iron oxide powder coating on a long strip of paper. A lot of innovations occurred in this field. AC biasing was one such innovation that dramatically improved the fidelity of the recorded audio signal by increasing the effective linearity of the recording medium.
Video Recording
Video signals were similar to audio signals. The main difference is that video signals required more bandwidth than audio signals. As a result, the existing audio tape recorders could not capture video signals effectively. The first successful video recording system was Quadruplex created by Charles Ginsburg and team at Ampex. This method used a spinning recoding head and normal tape speeds that achieved a very high head-to-tape speed that could record and reproduce the high bandwidth signals of video. This method used transverse scan for writing signals. Later improvements led to the development of helical scan and the enclosure of the tape reels in an easy-to-handle cartridge.
Magnetic Tape Data Storage
Magnetic tape was first used on the Eckert-Mauchly UNIVAC I in 1951. The recording medium was a thin strip of ½-inch wide nickel-plated bronze metal. Among the successful models were the earlier IBM tape drives that used vacuum columns to physically buffer long U-shaped loops of tape. Quarter inch cartridges were commonly used in the 1980s and 1990s. In late 1970s and early 1980s home computers used Compact Cassettes encoded with the Kansas City standard. Modern cartridge formats include LTO, DLT, and DAT/DDC.
