1957 Founded by Harlan Anderson and Kenneth H. Olsen. (2, p127-141)
- woolen mill on the Assabet River in Maynard, MA
- formerly made wool blankets for the Civil War

Ken Olsen
- involved with fitting Whirlwind with core memory
- was Lincoln Labs rep to IBM on SAGE
- in charge of Lincoln labs development of the TX-0

TX-0
- used new, faster "surface-barrier" transistors from Philco
- uses CRT and light pen
- operates in 1956
- Olsen takes CRT designer Ben Gurley with him to DEC

PDP-1 (based on TX-0 design)
- PDP = "Programmed Data Processor" (1, 224)
- uses transistors from the start
- uses DMA instead of I/O channels (becomes key feature of minis)
- uses multiple interrupt levels to handle the I/O
- PDP-1 at $120K costs less than a single IBM I/O channel
- sold only about 50 units
- PC(2): It is an architectural innovation comparable to von Neumann's EDVAC report.

DEC business posture
- sold, not leased
- encourages customer modification
- publishes and distributes cheap detailed specs about operation
- maintains liaison with BBN, MIT, etc.
- MIT students love it (Tech Model Railroad Controller, "hackers")
- one of the first "Route 128" companies
 

PDP-8
- 12 bit architecture
- influenced by Control Data Corporation 160A
- influenced by Lincoln Labs LINC (a personal lab computer)
- used fast germanium transistors

- 12 bit word limits memory access
- 7 bit address  - 128 words
- indirect addressing gets a 12 bit address - 4096 words
- divide memory into pages

- DEC tape (read or write either direction in 128 word blocks, LINC)
- Model ASR-33 (Automatic Send Receive) teletype
   o paper tape
   o ASCII character codes
   o control , escape and other special keys

- Required some programming skill

- sold 50,000 units at from $18-10K.

DEC work environment
- small, high quality engineering teams
- little management interference
- spartan and unpretentious
- sales force on salary, not commission

PDP-11 (2, 198-200)
- Unibus architecture
- Supports timesharing

PDP-10
- Introduced in 1966
- 36 bit machine
- Supports timesharing

DEC System 20
- Successor to PDP-10

VAX
- a family ranging from small to large systems
 

Some summary slides about DEC and its machines (3).

1998 Jun. Digital Equipment Corporation is acquired by Compaq Computer for $9.6 billion.

2002 May 3. Compaq Computer merges with Hewlett-Packard.

Notes

Selected Works of Digital Equipment Corporation

Robert W. Taylor, "In Memoriam: J. C. R. Licklider, 1915-1950," (Palo Alto, CA: System Research Center, Digital Equipment Corporation, 1990). Also available online at http://memex.org/licklider.pdf (memex.org, accessed 2003 Oct 24).

1. Martin Campbell-Kelly and William Aspray. Computer: A History of the Information Machine (Basic Books, 1996).

2. Paul E. Ceruzzi, A History of Modern Computing, 2nd ed. (Cambridge, MA: MIT Press, 2003).

3. Thomas J. Bergin, "Digital Equipment Corporation," http://www.csis.american.edu/museum/HOC_Class/html/slides/dec/sld001.htm (Computing History Museum, American University, accessed 2003 Nov 1).