Skip to main content

main memory

main memory (main store, main storage, RAM, primary memory) The storage that is closely associated with the processor of a computer system and from which the program instruction and data can be directly retrieved and to which the resulting data is written prior to transfer to backing store or output device. In modern machines this is semiconductor memory but in earlier machines core stores and delay lines were used.

The majority of storage activity generated by a processor in the execution of a program is directed at the main memory. In a modern processor, however, there is usually a further small high-speed memory interposed between the processor and main memory that holds recently accessed main-memory data for rapid re-access. This small high-speed memory is known as a cache. The main memory is normally used in conjunction with a backing store with a much larger capacity. See also memory hierarchy.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"main memory." A Dictionary of Computing. . Encyclopedia.com. 15 Oct. 2018 <http://www.encyclopedia.com>.

"main memory." A Dictionary of Computing. . Encyclopedia.com. (October 15, 2018). http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/main-memory

"main memory." A Dictionary of Computing. . Retrieved October 15, 2018 from Encyclopedia.com: http://www.encyclopedia.com/computing/dictionaries-thesauruses-pictures-and-press-releases/main-memory

Learn more about citation styles

Citation styles

Encyclopedia.com gives you the ability to cite reference entries and articles according to common styles from the Modern Language Association (MLA), The Chicago Manual of Style, and the American Psychological Association (APA).

Within the “Cite this article” tool, pick a style to see how all available information looks when formatted according to that style. Then, copy and paste the text into your bibliography or works cited list.

Because each style has its own formatting nuances that evolve over time and not all information is available for every reference entry or article, Encyclopedia.com cannot guarantee each citation it generates. Therefore, it’s best to use Encyclopedia.com citations as a starting point before checking the style against your school or publication’s requirements and the most-recent information available at these sites:

Modern Language Association

http://www.mla.org/style

The Chicago Manual of Style

http://www.chicagomanualofstyle.org/tools_citationguide.html

American Psychological Association

http://apastyle.apa.org/

Notes:
  • Most online reference entries and articles do not have page numbers. Therefore, that information is unavailable for most Encyclopedia.com content. However, the date of retrieval is often important. Refer to each style’s convention regarding the best way to format page numbers and retrieval dates.
  • In addition to the MLA, Chicago, and APA styles, your school, university, publication, or institution may have its own requirements for citations. Therefore, be sure to refer to those guidelines when editing your bibliography or works cited list.