The Digital Equipment Corporation PDP-8

by Douglas W. Jones
THE UNIVERSITY OF IOWA Department of Computer Science

The DEC PDP-8 computer, introduced 30 years ago on March 22, 1965, is generally recognized as the most important small computer of the 1960's. It was the least expensive parallel general purpose computer on the market, the first computer sold on a retail basis, and the first parallel general purpose digital computer sold in a table-top configuration.

Answers to Frequently Asked Questions

General information about the PDP-8 family of machines is contained in the alt.sys.pdp8 general FAQ. This is available from any of the following:

The Ohio State WWW site (recommended)
www.faqs.org (recommended)
The Usenet FTP archive (plain text)

Specific information about each PDP-8 model is contained in the alt.sys.pdp8 models and options FAQ. Taken together, this information constitutes a fairly complete history of the PDP-8; this is available from any of the following:

The Ohio State WWW site (recommended)
www.faqs.org (recommended)
The UNC PDP-8 FTP archive (plain text and out of date)

Programmer's Reference Material

A modern manual (under construction):

A Programmer's Reference Manual for the PDP-8

The pocket referencence cards listed below are reproductions of original DEC documentation distributed with the PDP-8:

The original 1965 reference card
The revised 1967 reference card
The 1974 PDP-8/E reference card

The following documents are reproductions of original DEC documentation:

FOCAL the original 1969 booklet and the UW FOCAL manual
Other original PDP-8 documentation

Hardware Reference Material

straight 8
8/E/F/M

Odds and Ends

My PDP-8 Collection

Trademarks used by Digital Equipment Corporation

A largely PAL-8 compatable cross assembler, Written in C, it is quite portable, and it produces either RIM or BIN format output.

An enhanced PAL-8 assembler is also available. This enhancement was written by Gary Messenbrink to support BART's fleet of PDP-8 systems.

A UNIX based PDP-8 emulator; this can be built for either X-Windows or dumb terminals. It is written in C, and it has been run under AIX, Solaris, and BSD UNIX, Linux and the Windows NT Posix environment. It has been tested under OS/8 running from an emulated RX01 diskette. Documentation of this emulator's data formats is available.

A collection of PDP-8 core images for the above emulator. Includes the RIM and BIN loaders (with source), FOCAL 1969, and RX01 bootstrap code.

an image of OS/8 Version 3Q on 2 RX01 diskettes bootable under the above emulator. Includes PAL8, DIRECT, PIP, EDIT, TECO, BASIC, F4 and more! (Note: As of Aug. 13, 1996, thanks to Bob Supnik, this is distributed with a free non-commercial use licence from DEC.)

Kermit the well known file transfer tool, a version for OS/8 mostly by Charles Lasner. As of January 2003, the official Kermit web site now supports the PDP-8 family of machines.

A UNIX based PDP-8 emulator for X-Windows, written in Modula-3 and tested under SunOS5. Explanatory notes are available.

Parse Software Devices Museum has a disassembler that can help reconstruct source code from RIM and BIN formatted paper tapes.

Notes on the History of the PDP-8

WWW pages organized by others

Institutional Pages

The Charles Babbage Institute; a scholarly institution devoted to the history of computing.

The Computer Museum History Center. While the original Computer Museum in Boston has gotten very much into computer literacy and touchy-feely displays on the innards of modern PCs, their excellent work on historical preservation has been taken up by this west-coast branch.

The Computer History Association of California; devoted to preserving the history of California's computer industry.

The Digital Alumni Inc, an alumni association for those who once worked at DEC.

The DFWLUG DECUS PDP-8/E; good photos of a nicely maintained PDP-8/E system in north Texas.

The Retro-Computing Society of Rhode Island; an informal association to further the preservation of vintage computers in southeastern New England.

The American Computer Museum of Bozeman, Montana.

The Historical Computer Society; their collection is currently limited to microcomputers, but their magazine, Historically Brewed, is promising but, so far, published only irregularly.

Private Collections

Paul Pierce's collection; his computer collection is huge, including everything from first generation mainframes to microcomputers, and his web pages include are on-line photos of many of his machines, including representative PDP-8 models.

Jay Jaeger's computer collection; a large collection with on-line photos of many nicely configured machines, including a PDP-8/L and a PDP-12, as well as related minicomputers from other manufacturers such as Data General and Hewlett Packard.

Jim's Computer Garage, run by Jim Willing. The minicomputer section includes an 8/I, 8/E and 8/M, with excellent photos and descriptions, including some internal details. The peripherals section includes a number of classic DEC peripherals, including the RK-05 hard drive, RX-02 floppy drive (with good photos of the internals) and the TU-55 and TU-56 DECtape drives..

PDP8.COM John Bradatanu's commercial venture in minicomputer restoration and maintenance. The writeup on the PDP-8/S includes a great quote from Saul Dinman about how the machine came to be and a photo of the original laboratory prototype Dinman built. There is also a good illustrated narative description of the restoration process for 8/S serial number 566.

Robert Krten's computer collection also known as the Parse Software Devices Museum, is dominated by PDP-8 and PDP-11 equipment. He has a nice page documenting the effort required to restore a PDP-8/I to working order.

Dan Mathias's collection is interesting, mostly microcomputers, but also a PDP-8/m, each item documented with a photo and minimal text.

Aaron's PDP-8 Page; Aaron Nabil's PDP-8 collection catalog. Aaron has been an important resource for PDP-8 collectors, but his web pages are not extensive.

Varga Akos Endre's collection is heavy on PDP-11 and VAX systems, but has interesting coverage of Hungarian clones from the cold war era, including some documentation for the TPA series of PDP-8, PDP-11 and VAX clones.

Bob's Computer Museum; Bob Manners has a growing collection, including a PDP-8/E; most of the photo illustrations are scanned in from PDP-8 handbooks.

Carl Friend's Minicomputer Museum; focuses on PDP-11 and Data General equipment, and has on-line photos of many machines and peripherals.

Eric Smith's collection; a balanced collection including 4 machines from the PDP-8 family.

Anthony Clifton's collecstion (and small business); heavy on microcomputers, but moving into bigger machines.

Other

The Virtual Museum of Computing (Oxford, UK); this is a serious attempt at creating an on-line museum, combining material created at Oxford with material available on the web.

The Computer Culture Museum (Germany); as with the above, this is a serious attempt to build an on-line (and physical) museum of computing.

Megan Gentry's home page; this includes links to information on many DEC computers and sources for Robert Supnik's emulators for many DEC computers.