Digital PDP-11/20

The PDP-11 was an extremely successful and influential family of machines which has spanned over two decades from the early 1970s through the mid 1990s. The first PDP-11 in 1970 cost $10,800 and was DEC's first and only 16 bit computer.

The 11/04 (September 1975) was an implementation of the Unibus pdp-11 architecture, and was essentially a replacement for the 11/05 & 11/10. It was the first pdp-11 to escape without a 'proper' lights & switches front panel, instead it had the glorified 'programmers console' as an option - a hex keypad and an LED display which showed address/data digitally.

It came in two chassis, like the 11/05 & 11/10 - a half-height example, which had the entire Unibus backplane, power supply, front panel - basically the whole computer - sliding into an evil jamming finger-trapping metal sleeve - and a full-height example, basically the same BA11 box as used by the 11/35 and many many other DEC applications. It's very similar to its higher-spec twin, the 11/34. Our model is the half height one.

The PDP 11/04 is a Unibus based 16-bit minicomputer which included the following boards:
M7263 KD11-D 11/04 processor module
M7847-DJ MS11-JP 16-Kword 18-bit RAM
M9312 Bootstrap terminator with 5 empty ROM sockets
M7859 KY11-LB Console interface; programmer's console
M7856 DL11-W RS-232 SLU & realtime clock option
G7273 Bus Grant & Non-processor grant
M8256 RX211 RX02 floppy disk controller


Manufacturer: Digital
Date: 1971



Comment on This Page

Other Systems Related To Digital PDP-11/20:

Item Manufacturer Date
Digital PDP-11/04 BD Digital July 1976
Digital PDP-11/60 System Digital 1977
Digital PDP-11/34 Digital 1978
Digital PDP-11/35 System Digital 1978
Digital Systems DMS 3 Digital Microsystems 1982
Digital Professional 350-D Digital 1982
DEC Rainbow 100+ Digital Equipment Corporation 1982
DEC Rainbow Digital Equipment Corporation 1982
DECmate II Digital Equipment Corporation 1982
Digital Microsystems DMS816 Digital Microsystems 1983
DECMate III Digital Equipment Corporation 1984
TK90X Color Computer Microdigital 1985
DEC Microvax 2 Digital Equipment Corporation May 1985
Digital MicroVAX 3100 Digital 1987
Digital MicroVAX 3100-80 Digital 1989
Digital DEC 3000/600 Digital 13th October 1993
Digital DEC Multia (Alpha Generation) Digital 7th November 1994
Digital PC 425SL/e Digital 1996
Digital Personal Workstation 433au Digital Equipment Corporation 1997
Digital AlphaServer A4100 Digital 1998

This exhibit has a reference ID of CH51050. Please quote this reference ID in any communication with the Centre for Computing History.

 

Digital PDP-11/20

  Book Archive   [1]

Click on the Image(s) For Detail


User Submitted Articles


Add Your Article >>>

Help support the museum by buying from the museum shop

View all items

Founding Sponsors
redgate Google ARM Real VNC Microsoft Research
Heritage Lottery Funded
Heritage Lottery Fund
Accredited Museum