Editing Programmed Data Processor (section)

{{Short description|Name used for several lines of minicomputers}}
[[File:PDP-1.jpg|thumb|PDP-1]]
[[File:Dec pdp-6.lg.jpg|thumb|PDP-6]]
[[File:Pdp7-oslo-2005.jpeg|thumb|PDP-7]]
[[File:DEC PDP 8e.jpg|thumb|PDP-8/e]]
[[File:Pdp-11-40.jpg|thumb|PDP-11/40]]
[[File:PDP-12-Update-Uppsala.jpeg|thumb|PDP-12]]
[[File:PDP-15 at Varesezaal.jpg|thumb|PDP-15 (partial)]]
[[File:PDP-15 graphics terminal.agr.jpg|thumb|PDP-15 graphics terminal with [[light pen]] and [[Graphics tablet|digitizing tablet]] ]]

'''Programmed Data Processor''' ('''PDP'''), referred to by some customers, media and authors as "'''Programmable''' Data Processor,"<ref>{{cite web
|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19860004398.pdf
|title=VAS Demonstration  |website=nasa.gov|date=October 1985 |last1=Montgomery |first1=H. E. |last2=Uccellini |first2=L. W. }}</ref><ref>{{cite web
 |website     = harvard.edu
 |url         = http://www.innovation.seas.harvard.edu/files/Disruptive_technology.ppt
 |title       = New Market Disruption: The DEC Programmable Data Processor
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20170915114458/http://www.innovation.seas.harvard.edu/files/Disruptive_technology.ppt
 |archive-date = 2017-09-15
}}</ref><ref>{{cite book  |title=Computers in Analytical Chemistry
|page=153 |url=https://books.google.com/books?isbn=1483285626  |isbn=978-1483285627 |author=R Belcher   |date=2013}} 
"The term PDP is an acronym for Programmable Data Processor ... the series was introduced by their manufacturer, Digital Equipment Corporation ..."</ref> is a term used by the [[Digital Equipment Corporation]] from 1957 to 1990 for several lines of [[minicomputer]]s.<ref name=DEC_Hist>{{cite web
|url=https://digital.com/about/dec |title=The History of Digital Equipment Corporation}}</ref>

The name "PDP" intentionally avoids the use of the term "computer". At the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines. The [[venture capital]]ists behind Digital (especially [[Georges Doriot]]) would not support Digital's attempting to build a "computer" and the term "minicomputer" had not yet been coined.<ref>{{cite book|editor-last1=Henderson|editor-first1=Rebecca M.|editor-last2=Newell|editor-first2=Richard G.|title=Accelerating energy innovation : insights from multiple sectors|date=2011
|publisher=University of Chicago Press|location=Chicago|isbn=978-0226326832|page=180}}</ref><ref>{{cite book|last1=Huang
|first1=Han-Way|title=The atmel AVR microcontroller : MEGA and XMEGA in assembly and C|date=2014
|publisher=Delmar Cengage Learning|location=Australia ; United Kingdom|isbn=978-1133607298|page=4}}</ref> So instead, Digital used their existing line of logic modules to build a ''Programmed Data Processor'' and aimed it at a market that could not afford the larger computers.

The various PDP machines can generally be grouped into families based on [[word length]].