The Digital Equipment Corporation PDP-8

The DEC PDP-8 computer, introduced over 60 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.

General

The DEC PDP-8 Story

• Part I — the beginning (HTML version)
• Part II — the minicomputer revolution
• Part III — the concluding years

I wrote the above to put the PDP-8 in its historic context. Part I was published in Historically Brewed, 7 (Sept/Oct 1994), published by the Historical Computer Society.

Frequently Asked Questions

• The general FAQ answers most questions.
• The PDP-8 Models and Options page gives more detail.

The above pages replace and expand on FAQ pages that were formerly distributed in the alt.sys.pdp8 newsgroup back in the 1990s.

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

• The University of Iowa PDP-8
• 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 is based on an enhancement of the above by Gary Messenbrink to support BART's fleet of PDP-8 systems, and has seen additional improvement under David Gesswein's curatorship.

• A UNIX based PDP-8/E emulator (shell archive); 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 in Unix shell archive (shar) format for the above emulator. Includes the RIM and BIN loaders (with source), FOCAL 1969, RX01 bootstrap code and a VC8E demo program.

• 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.

• Robert Krten 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. They house the corporate archives of many former computer manufacturers.

• The Computer History Museum. While the original Computer Museum in Boston wandered 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 (British) National Museum of Computing, at Bletchley Park. They have an extraordinary collection.

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

• The Retro-Computing Society of Rhode Island; began as an informal association to further the preservation of vintage computers in southeastern New England. They have an open house on the third Saturday of every month, and their collection includes a LINC-8 and numerous more recent PDP-8 systems.

• The American Computer Museum of Bozeman, Montana. They have a table-top classic PDP-8.

• (Defunct link) The Computer History Association of California; devoted to preserving the history of California's computer industry.

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

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

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.

• 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 good working PDP-8/m. Each item documented with a photo and minimal text. Mathias's web site is primarily devoted to pdp-8.org Aaron Nabil's PDP-8 documentation catalog. Aaron has been an important resource for PDP-8 collectors, but his web pages are not extensive.

• Carl Friend's Minicomputer Museum; focuses on PDP-11 and Data General equipment, but has both a LINC-8 and an 8/I. There are some decent on-line photos of many machines and peripherals.

• Eric Smith's collection; a balanced collection including 4 machines from the PDP-8 family. No photos, but extensive lists of links to information sources.

• (Defunct link) 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..

• (Defunct link) 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.

• (Defunct link) 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.

• (Defunct link) 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.

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

Other

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

• (Defunct link) 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.

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