[sahy-kuh
l] 
noun, verb, -cled, -cling.| 1. | any complete round or series of occurrences that repeats or is repeated. |
| 2. | a round of years or a recurring period of time, esp. one in which certain events or phenomena repeat themselves in the same order and at the same intervals. |
| 3. | any long period of years; age. |
| 4. | a bicycle, motorcycle, tricycle, etc. |
| 5. | a group of poems, dramas, prose narratives, songs etc., about a central theme, figure, or the like: the Arthurian cycle. |
| 6. | Physics.
|
| 7. | Mathematics. a permutation of a set of elements that leaves the original cyclic order of the elements unchanged. |
| 8. | Computers.
|
| 9. | to ride or travel by bicycle, motorcycle, tricycle, etc. |
| 10. | to move or revolve in cycles; pass through cycles. |
| 11. | hit for the cycle, Baseball. (of one player) to hit a single, double, triple, and home run in one game. |
| cy·cle (sī'kəl) n.
v. intr.
To use in or put through a cycle: cycled the heavily soiled laundry twice; cycling the recruits through eight weeks of basic training. [Middle English, from Late Latin cyclus, from Greek kuklos, circle; see kwel-1 in Indo-European roots.] cy'cler n. |
cycle cy·cle (sī'kəl)
n.
An interval of time during which a characteristic, often regularly repeated event or sequence of events occurs.
A single complete execution of a periodically repeated phenomenon.
A periodically repeated sequence of events.
cycle unit
A basic unit of computation, one period of a computer clock.
Each instruction takes a number of clock cycles. Often the computer can access its memory once on every clock cycle, and so one speaks also of "memory cycles".
Every hacker wants more cycles (noted hacker Bill Gosper describes himself as a "cycle junkie"). There are only so many cycles per second, and when you are sharing a computer the cycles get divided up among the users. The more cycles the computer spends working on your program rather than someone else's, the faster your program will run. That's why every hacker wants more cycles: so he can spend less time waiting for the computer to respond.
The use of the term "cycle" for a computer clock period can probably be traced back to the rotation of a generator generating alternating current though computers generally use a clock signal which is more like a square wave. Interestingly, the earliest mechanical calculators, e.g. Babbage's Difference Engine, really did have parts which rotated in true cycles.
[The Jargon File]
(1997-09-30)
