The PDP-8 Family

Digital Equipment Corporation PDP-5

This was the first machine with the 12-bit architecture and instruction set later found in all PDP-8 computers. It was contemporary with (but later than) the Packard Bell PB-250. Built with 6 microsecond core memory, discrete metal-can transistors and a hand-soldered backplane, it was too slow and expensive to be very successful. The PDP-5 in the collection was originally purchased by Westinghouse for the NIRVA atomic rocket project in the 60's. I don't have a picture of it yet.

PDP-8

Built with discrete plastic "Flip Chip" transistors, this was the first computer for less than $25,000. It was cheap enough to be purchased for individual projects. Its 1.5 microsecond core memory made it fast enough to be useful on a wide range of applications from scientific research to typesetting. Here is a closeup of the front panel lights and switches. The PDP-8 in the collection is a basic model, with 4K words of core and a teletype. more...

PDP-8/I

The successor to the Classic 8 was the first to use TTL integrated circuits. It was less expensive and somewhat smaller, but the same speed. more...

PDP-12

This was a combination PDP-8 and MIT LINC built out of TTL like the PDP-8/I. It has a single processor with two instructions sets and can switch back and forth between them. The LINC was designed to be a laboratory computer and the PDP-12 came with builtin A/D and D/A converters, relays, timers, and an X-Y display. more...

PDP-8/e

The most popular PDP-8, it was smaller, faster and less expensive than the PDP-8/I. The PDP-8/e in the collection is the most complete with many different peripherals. more...

PDP-8a

The PDP-11, which came out about the same time as the PDP-8/e, soon eclipsed the PDP-8 family. Still new models were made for applications such as the new "word processing". The picture shows a DECSystem 310, which has a PDP-8a in the back of the desk. There is normally a DEC VT-52 video terminal in the well in front. Files were stored on 8 inch floppy disks using the two drives on the left. more...

WT78

Based on the Intersil 6100 microprocessor, this was built to run the same word processing software as the PDP-8a but it fits entirely inside the case of the video terminal. more...

More on the PDP-8 family in the library...

More pictures of these computers.

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