Clocks are in homes, offices and many other places; smaller ones (watches) are carried on the wrist or in a pocket; larger ones are in public places, e.g. a railway station or church. A small clock is often shown in a corner of computer displays, mobile phones and many MP3 players.
The purpose of a clock is not always to display the time. It may also be used to control a device according to time, e.g. an alarm clock, a VCR, or a time bomb (see: counter). However, in this context, it is more appropriate to refer to it as a timer or trigger mechanism rather than strictly as a clock.
Computers depend on an accurate internal clock signal to allow synchronized processing. (A few research projects are developing CPUs based on asynchronous circuits.) Some computers also maintain time and date for all manner of operations whether these be for alarms, event initiation, or just to display the time of day. The internal computer clock is generally kept running by a small battery. Many computers will still function even if the internal clock battery is dead, but the computer clock will need to be reset each time the computer is restarted, since once power is lost, time is also lost.
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Famous quotes containing the word purposes:
“I have been reporting club meetings for four years and I am tired of hearing reviews of the books I was brought up on. I am tired of amateur performances at occasions announced to be for purposes either of enjoyment or improvement. I am tired of suffering under the pretense of acquiring culture. I am tired of hearing the word culture used so wantonly. I am tired of essays that let no guilty author escape quotation.”
—Josephine Woodward, U.S. author. As quoted in Everyone Was Brave, ch. 3, by William L. ONeill (1969)
“Researchers, with science as their authority, will be able to cut [animals] up, alive, into small pieces, drop them from a great height to see if they are shattered by the fall, or deprive them of sleep for sixteen days and nights continuously for the purposes of an iniquitous monograph.... Animal trust, undeserved faith, when at last will you turn away from us? Shall we never tire of deceiving, betraying, tormenting animals before they cease to trust us?”
—Colette [Sidonie Gabrielle Colette] (18731954)
“One of the baffling things about life is that the purposes of institutions may be ideal, while their administration, dependent upon the faults and weaknesses of human beings, may be bad.”
—Mary Barnett Gilson (1877?)