Analog technology dominated the audio industry for more than a century. Beginning with the first primitive analog devices of the 1870s, they were often the sole viable means of recording sound until the introduction of the compact disc in the 1980s. Other analog devices were introduced, including analog computers. Analog has largely been replaced by digital formatting, but it still clings to life in certain applications.
Identification
Analog refers to a process for recording information by copying it as a continual wave in or on the media. This is a different and older method of recording data from digital means, which operates by converting data into binary numbers.
Analog Media
There are two major forms of audio analog media: magnetic tape and the gramophone record. Although digital CD and MP3 technology has largely superseded these analog technologies, neither has become entirely obsolete and disappeared from regular use. Magnetic tape was also used as a medium for data storage in early computers, and some computers like the Polish AKAT-1 were non-digital, all-analog devices.
Analog Function
The gramophone record (often simply "record") is usually made from vinyl. The method used for putting audio information on a record is called groove recording, first developed for practical use by Thomas Edison in 1877. Disc records using this technology were first invented in 1888, but records as they are commonly thought of did not enter circulation until the early 20th Century.
Magnetic tape recording works by imprinting a magnetic signal onto the tape, and then reading it back while the tape is played at a constant speed. The format has taken many forms, from reel-to-reel to 8-track to cassette tape. The earliest practical examples used a wire and date to 1929.
Digital Function
The compact disc is an optical medium for storing digital data. As a practical matter, the only difference between the music a CD was originally invented to record, and the common data storage use of today, is the contents of the disc and the device that is reading it. Data is encoded onto a CD through a series of minuscule indentations called "pits." The spaces between pits are called "lands." The changes between pits and lands are read as binary code by a scanning laser.
Digital computing also works through the manipulation of vast amounts of data, being represented by a long string of binary code. This is possible because a typical desktop computer is capable of making billions of binary instructions per second.
Analog Computers
An analog computer was a curious early experiment in computing technology. Like a digital computer, it used electricity. However, instead of using electric pulses in digital code, the analog computer used them in substitution for the mechanics that had previously been used in mechanical and hydraulic computer designs (such as were used in World War II era gun sights).
Old Style Digital
Digital formats have actually been around for much longer than modern computing. Morse Code, for example, is a digital system.
Tags: analog computer, analog devices, between pits, binary code, compact disc, computer used
