PDP-9
{{Short description|18-bit computer from Digital, 1966}}
{{Infobox computing device
| name = PDP-9
| title =
| aka =
| logo = PDP-9 wordmark.svg
| image = File:PDP-9.jpg
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| developer = Digital Equipment Corporation
| manufacturer =
| family = Programmed Data Processor
| type = Minicomputer
| generation =
| releasedate = {{Start date and age|1966}}
| lifespan =
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| discontinued =
| unitssold = 445
| unitsshipped =
| media = Paper tape, DECtape
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| memory card =
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| platform = DEC 18-bit
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| dimensions =
| weight = {{convert|750|lb|kg}}
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| predecessor = PDP-7
| successor = PDP-15
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}}
The PDP-9, the fourth of the five 18-bit minicomputers produced by Digital Equipment Corporation, was introduced in 1966.{{cite book
|title=DIGITAL EQUIPMENT CORPORATION - Nineteen Fifty-Seven To The Present
|url=http://s3data.computerhistory.org/pdp-1/dec.digital_1957_to_the_present_(1978).1957-1978.102630349.pdf
|date=1975 |publisher=Digital Equipment Corporation}}{{RP|P.10}} A total of 445 PDP-9 systems were produced,{{cite web |url=https://www.ricomputermuseum.org/collections-gallery/equipment/dec-pdp-9
|title=RI Computer Museum, DEC PDP-9, System Number 319}} of which 40 were the compact, low-cost PDP-9/L units..{{cite web |url=http://www.quadibloc.com/comp/pan07.htm |title=The Early Architectures of DEC}}
History
Hardware
The PDP-9, which is "two metres wide and about 75cm deep,"{{cite web
|url=https://50years.latrobe/david-millsom |title=David Millson - 50 years}} is approximately twice the speed of the PDP-7. It was built using discrete transistors, and has an optional integrated vector graphics terminal. The PDP-9 has a memory cycle time of 1 microsecond, and weighs about {{convert|750|lb|kg}}.{{cite book|url=http://www.bitsavers.org/pdf/dec/pdp9/F-97_PDP-9_MaintMan_Apr72.pdf|title=PDP-9 Maintenance Manual, Volume 1|date=April 1972}}{{rp|pages=1{{hyphen}}7-1{{hyphen}}8}} The PDP-9/L has a memory cycle time of 1.5 microseconds, and weighs about {{convert|900|lb|kg}}.{{cite book|title=PDP-9/L User Handbook|url=http://www.bitsavers.org/pdf/dec/pdp9/pdp9l/DEC-9L-GRVA-D_PDP9L_Hbk.pdf|pages=|date=June 1968}}{{rp|page=1{{hyphen}}1, 15{{hyphen}}8}}
It is DEC's first microprogrammed machine.{{cite book|chapter-url=https://books.google.com/books?id=SDOoBQAAQBAJ&pg=PA154|title=Computer Engineering: A DEC View of Hardware Systems Design|chapter=Chapter 6: The PDP-1 and Other 18-bit Computers|author1=C. Gordon Bell|authorlink1=Gordon Bell|author2=Gerald Butler|author3=Robert Gray|author4=John E. McNamara|author5=Donald Vonada|author6=Ronald Wilson|pages=154–155|editor1=C. Gordon Bell|editor2=J. Craig Mudge|editor3=John E. McNamara|publisher=Digital Press|year=1978|isbn=0-932376-00-2}}{{rp|page=3{{hyphen}}16}}
A typical configuration included:
- 300 cps paper tape reader
- 50 cps paper tape punch
- DECtape for operating system and user files
- 10 cps console teleprinter, Model 33 KSR
Among the improvements of the PDP-9 over its PDP-7 predecessor are:
- the addition of status flags for reader and punch errors, thus providing added flexibility and for error detection{{cite web
|url=http://www.soemtron.org/downloads/decinfo/architecture18b-08102006.pdf
|title=Architectural Evolution in DEC's 18b Computers |author=Bob Supnik}}
- an entirely new design for multi-level interrupts, called the Automatic Priority Interrupt (API) option
- a more advanced form of memory management{{cite web
|url=https://github.com/parsa/simh/wiki/PDP-9-Simulator-Configuration
|title=PDP 9 Simulator Configuration |website=GitHub.com}}
User/university-based research projects for extending the PDP-9 include:
- a hardware capability for floating-point arithmetic, at a time when machines in this price range used software for floating-point arithmetic{{cite thesis
|url=http://arizona.openrepository.com/arizona/handle/10150/318186
|title=Design of a floating point processor for the PDP-9 computer
|degree=MSc
|publisher=University of Arizona |author=Ben Milton Huey |date=1969}}
- a PDP-9 controlled parallel computer{{cite thesis
|url=http://arizona.openrepository.com/arizona/handle/10150/347638
|title=The logic design of a PDP-9 controlled parallel computer
|degree=MSc
|publisher=University of Arizona |author=Wokhlu, Roop Krishen |date=1969}}
Software
The system came with an OS that functions as single-user keyboard monitor, called ADSS (ADvanced Software System).{{cite web
|url=http://www.bitsavers.org/pdf/dec/spd/17.06.00_7608_ADSS-B_F-15_5C.pdf
|title=Software Product Description, ADSS-B/F-15, Version SC, Advanced Software System, B/F |author=Digital Equipment Corporation}} DECsys provided an interactive, single-user, program development environment for Fortran and assembly language programs.{{cite web
|url=http://simh.trailing-edge.com/docs/decsys.pdf
|title=Technical Notes on DECsys |author=Bob Supnik |date=19 June 2006}}
Both FORTRAN II and FORTRAN IV{{cite web
|url=http://www.silogic.com/Athena/Hybrid%20Lab/1968%20CMU%20Hybrid%20Lab%20-%20Linkage%20-%20PDP-9%20Facilities.pdf
|title=User Manual - Linkage - PDP-9 Facilities |publisher=Carnegie-Mellon University Hybrid Computation Laboratory |date= September 1968 |access-date= 19 September 2017}} were implemented for the PDP-9.
MUMPS was originally developed on the PDP-7, and ran on several PDP-9s at the Massachusetts General Hospital.
Sales
The PDP-7, of which 120 were sold,{{rp|p.8}} was described as "highly successful". The PDP-9 sold 445 units. Both have submodels, the PDP-7Asometimes identified by customers and media as PDP-7/A and the PDP-9/L,yes, DEC had a "slash" for the 9/L but not for the 7A neither of which accounted for a substantial percentage of sales.directly mentioned for one, calculated in the other case
See also
- Programmed Data Processor
- PDP-15 - successor to the PDP-9
Notes
{{reflist|group="NB"}}
References
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{{DEC hardware}}
Category:Transistorized computers
Category:Computer-related introductions in 1966
{{mini-compu-stub}}