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Manufacturer DEC - Digital Equipment Corporation
Identification,ID PDP-6
Date of first manufacture1964
Number produced 23*
Estimated price or cost-
location in museum -
donor -

Contents of this page:



36 bit word - sub set of later PDP-10

See Instruction List of PDP-10

From "Digital at Work" , Digital Press, copyright 1992, page 54
                Specification - PDP-6

First shipped
    June 1964
Word length
    36 bits
    0.25 MIPS
    18-bit physical address protection
    and relocation registers
Instruction set
    2's complement
    I/O and memory bus
    FORTRAN compiler, text editor,
    a debugger(DDT),copy program
    called PIP (Peripheral Interchange
    Program), assembler
    Designed for timesharing and
    real-time lab use, with straightforward
    interfacing capability, served as
    PDP-10 production prototype

The 36-Bit Family: The Courage to Invest in New Technology The first deliveries of the computer Digital called its "most dramatic" came even before the PDP-8, in the summer 1964. The PDP-6 was shipped to MIT's Project MAC (known variously as Multiple Access Computing and Machine Aid Cognition), the University of Western Australia, Brookhaven National Laboratory, and Lawrence Livermore National Laboratory.

PDP-6: A Personal Mainframe The PDP-6 originally was designed to extend the performance of Digital's 18-bit processor series, but several facto influenced the course of the new design.

First, 36 bits was the standard for scientific computing. This extended word length also accommodated LISP, a new language developed for work in artificial intelligence, still an active subject of university computing research. Finally, competing with IBM mainframes meant producing Digital's own 36-bit machines.

The PDP-6 was designed as a new kind of mainframe, to be used for both timesharing and real-time laboratory applications, with straightforward interfacing capability. It was the first of what might be called a "personal" mainframe. It also was the first commercial computer available with software for timesharing applications.

Although system sales were only 23, the PDP-6 had a much greater influence than its small number would suggest. Most were sold to universities, where a new generation of computer scientists was introduced to the idea of interactive, time-shared computing. Although compatibility was not a specified design goal, the series evolved into five basic designs over 18 years-PDP-6, KAl0, KIl0, KL10, and DECSYSTEM-20. ByJanuary of 1978 more than 700 systems would be installed.

The PDP-10 came next, followed by be DECsystem-10 and DECSYSTEN-20 series: large systems, all designed to give each user the illusion of having his own large computer. They offered economical cost per user via timesharing for commercial, scientific,and communication applications and eliminated the long wait for results associated with batch processing.

           36-Bit Family Timeline

1964	PDP-6, Digital's first large,36-bit computer
1966	PDP-10 succeeds PDP-6
	Model KA10, first Digital large system in production
1971	First DECsystem-10
1972	DECsystem-10 1ine offers unrivaled expansion
	K110 model offers high performance in
	scientific and real-time applications
	TOPS-10 operating system
1975	KL10 introduced as two new DECsystem-10
	models, 1080 and 1090
1978	DECSYSTEM-20, aka 2040, lowest-priced commercial
	timesharing system
	DECsystem-1088, a dual 1080, most
	powerful Digital systems to date
1977	DECSYSTEM-2050 and full line of
	peripheral systems.
	TDPS-20 operating system
1980      DECSYSTEM-2020 released. Came with a KS processor
         that operated at 20% of the lowest-cost KL processor.
1983	Digital stops developing DECsystem-10 and
         DECSYSTEM-20 systems. Continues
        support by converting users to VAX-based

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Thanks to Joe Smith for numerous corrections to ORDed text.

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Updated August 15, 2004