Editing PDP-10 (section)

{{Short description|36-bit computer by Digital (1966–1983)}}
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{{Infobox information appliance
| name         = PDP-10
| title        =
| aka          = DECsystem-10
| logo         = decsystem.svg
| logo_size    = 250px
| logo caption =
| image        = DEC PDP-10 (from ca. 1970 named decsystem-10) mainframe computer system, 1970s (edited, white background).jpg
| image_size   = 250px
| caption      = Working DEC KI-10 System formerly at Living Computers: Museum + Labs
| developer    = [[Digital Equipment Corporation]]
| manufacturer =
| family       = [[Programmed Data Processor]]
| type         = [[Mainframe computer]] 
| generation   =
| releasedate  = {{Start date and age|1966}}
| lifespan     =
| price        =
| discontinued = {{End date and age|1983}}
| unitssold    =
| unitsshipped =
| media        =
| os           = [[Incompatible Timesharing System|ITS]], [[TOPS-10]], [[TENEX (operating system)|TENEX]], [[WAITS]], [[CompuServe]] time-sharing system
| power        =
| soc          =
| cpu          =
| memory       =
| storage      =
| memory card  =
| display      =
| graphics     =
| sound        =
| input        =
| controllers  =
| camera       =
| touchpad     =
| connectivity =
| platform     = DEC 36-bit
| service      =
| dimensions   =
| topgame      =
| compatibility=
| predecessor  = [[PDP-6]]
| successor    =
| related      = [[DECSYSTEM-20]]
| website      =
}}
[[File:Arpanet logical map, march 1977 PDP-10.png|thumb|right|300px|PDP-10 systems on the ARPANET highlighted in yellow]]
[[Digital Equipment Corporation]] (DEC)'s '''PDP-10''', later marketed as the '''DECsystem-10''', is a [[mainframe computer]] family<ref>Ceruzzi, p. 208, "It was large&mdash;even DEC's own literature called [the PDP-10] a mainframe."</ref> manufactured beginning in 1966<ref>Ceruzzi, p. 139</ref> and discontinued in 1983.<ref>{{cite book |last=Winstanley |first=Graham |date=1991 |title=Artificial intelligence in engineering |location=West Sussex, England |publisher=Wiley, Chichester |page=391 |isbn=9780471926030 |quote=PDP-10...was discontinued in 1983}}</ref><ref>{{cite web
|title=PDP-10 was discontinued in 1983, but PDP-11 wasn't discontinued until 1997
|url=https://news.ycombinator.com/item?id=13469933
|quote=... with third-parties continuing to sell parts, so it's really not that ...}}</ref><ref>{{cite web  |title=What does pdp-10 mean? |url=https://www.definitions.net/definition/pdp-10
|website=definitions.net |quote=The PDP-10 was a mainframe computer family manufactured ... the cancellation of the PDP-10 line was announced in 1983.}}</ref> 1970s models and beyond were marketed under the DECsystem-10 name, especially as the [[TOPS-10]] operating system became widely used.{{efn|The TOPS-10 name was announced 1970}}

The PDP-10's architecture is almost identical to that of DEC's earlier [[PDP-6]], sharing the same [[36-bit]] [[Word (computer architecture)|word]] length and slightly extending the instruction set. The main difference was a greatly improved hardware implementation. Some aspects of the [[instruction set]] are unusual, most notably the ''[[byte]]'' instructions, which operate on [[bit field]]s of any size from 1 to 36 bits inclusive, according to the general definition of a byte as ''a contiguous sequence of a fixed number of bits''.

The PDP-10 was found in many university computing facilities and research labs during the 1970s, the most notable being [[Harvard University]]'s Aiken Computation Laboratory, [[Massachusetts Institute of Technology|MIT]]'s [[MIT Computer Science and Artificial Intelligence Laboratory#LCS and AI Lab|AI Lab]] and [[MIT Computer Science and Artificial Intelligence Laboratory#Project MAC|Project MAC]], [[Stanford University|Stanford]]'s [[Stanford AI Lab|SAIL]], [[Computer Center Corporation]] (CCC), [[ETH]] (ZIR), and [[Carnegie Mellon University]]. Its main [[operating system]]s, TOPS-10 and [[TENEX (operating system)|TENEX]], were used to build out the early [[ARPANET]]. For these reasons, the PDP-10 looms large in early [[Hacker culture|hacker folklore]].

Projects to extend the PDP-10 line were eclipsed by the success of the unrelated [[VAX]] [[superminicomputer]], and the cancellation of the PDP-10 line was announced in 1983. According to reports, DEC sold "about 1500 DECsystem-10s by the end of 1980."<ref name=Foonly.MMSmag1980>{{cite magazine|magazine=Mini-Micro Systems
   |title=Foonly challenges DEC patents with emulator
   |author=Larry Lettieri |date=November 1980 |pages=15, 17}}</ref>