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| CATEGORIES ABOUT MAGNETIC STORAGE | |
| computer storage media | |
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HISTORY Magnetic storage was first suggested by Oberlin Smith in 1888. The first working magnetic recorder was invented by Valdemar Poulsen in 1898. Poulsen's device recorded a Signal on a wire wrapped around a drum. In 1928, Fritz Pfleumer developed the first magnetic tape recorder. Early magnetic storage devices were designed to record Analog audio signals. Modern magnetic storage devices are designed for recording Digital data. In early computers, magnetic storage was also used for Primary Storage in a form of Magnetic Drum , or Core Memory , Core Rope Memory , Thin Film Memory , Twistor Memory or Bubble Memory . Also unlike modern computers, magnetic tape was often used for secondary storage. TECHNICAL DETAILS Access method Magnetic storage media can be classified as either Sequential Access Memory or Random Access Memory although in some cases the distinction is not perfectly clear. In the case of magnetic wire, the read/write head only covers a very small part of the recording surface at any given time. Accessing different parts of the wire involves winding the wire forward of backward until the point of interest is found. The time to access this point depends on how far away it is from the starting point. The case of ferrite-core memory is the opposite. Every core location is immediately accessible at any given time. Hard disks and modern linear serpentine tape drives do not precisely fit into either category. Both have many parallel tracks across the width of the media and the read/write heads take time to switch between tracks and to scan within tracks. Different spots on the storage media take different amounts of time to access. For a hard disk this time is typically less than 10 ms, but tapes might take as much as 100 s. CURRENT USAGE As of 2007, common uses of magnetic storage media are for computer data mass storage on hard disks and the recording of analog audio and video works on Analog Tape . Since much of audio and video production is moving to digital systems, the usage of hard disks is expected to increase at the expense of analog tape. Digital Tape and Tape Libraries are popular for the high capacity data storage of archives and backups. Floppy Disk s see some marginal usage, particularly in dealing with older computer systems and software. Magnetic storage is also widely used in some specific applications, such as bank checks ( MICR ) and payment cards ( Mag Stripes ). FUTURE
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