<unit, data>

(PB) A unit of data equal to one quadrillion bytes but see binary prefix for other definitions. A petabyte is 10^15 bytes or 1000^5 bytes or 1000 terabytes.

As of 2013-11-05, the Internet Archive Wayback Machine contains almost two petabytes of data.

A petabyte is the amount of data that would be required to store a 2000 by 1600 pixel image of every one of the 314 million people living in the USA in 2012.

1000 petabytes are one exabyte.

See prefix.

Last updated: 2007-09-13



10^15 flops or 1000 teraflops.

As with flops, the term ends in S in both the singular and plural as the S stands for seconds.

The first computer to perform one petaflops was recorded in June 2008. By June 2012 there were 20.

Last updated: 2013-04-27



An Estelle to C++ translator.

Last updated: 1997-01-24

Peter P. Chen


The developer of the Entity-Relationship model.

Last updated: 1995-02-07

Petri net

<parallel, simulation>

A directed, bipartite graph in which nodes are either "places" (represented by circles) or "transitions" (represented by rectangles), invented by Carl Adam Petri. A Petri net is marked by placing "tokens" on places. When all the places with arcs to a transition (its input places) have a token, the transition "fires", removing a token from each input place and adding a token to each place pointed to by the transition (its output places).

Petri nets are used to model concurrent systems, particularly network protocols.

Variants on the basic idea include the coloured Petri Net, Time Petri Net, Timed Petri Net, Stochastic Petri Net, and Predicate Transition Net.


Last updated: 1996-09-10



/pet'skee/ PET ASCII. The variation (many would say perversion) of the ASCII character set used by the Commodore Business Machines' PET series of personal computers and the later Commodore 64, Commodore 16, and Commodore 128 computers. The PETSCII set used left-arrow and up-arrow (as in old-style ASCII) instead of underscore and caret, placed the unshifted alphabet at positions 65--90, put the shifted alphabet at positions 193--218, and added graphic characters.

[Jargon File]

Last updated: 1995-10-29

Nearby terms:

pessimalpessimising compilerpeta-petabytepetaflopspetdingo

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