The PDP-8 is a 12-bitminicomputer that was produced by Digital Equipment Corporation (DEC). It was the first commercially successful minicomputer, with over 50,000 units being sold over the model’s lifetime. Its basic design follows the pioneering LINC but has a smaller instruction set, which is an expanded version of the PDP-5 instruction set.[1] Similar machines from DEC are the PDP-12 which is a modernized version of the PDP-8 and LINC concepts, and the PDP-14industrial controller system.

PDP-8

A PDP-8 on display at Bletchley Park in Bletchley, England. This example is from the first generation of PDP-8s, built with discrete transistors and later known as the Straight 8.
Developer	Digital Equipment Corporation
Product family	Programmed Data Processor
Type	Minicomputer
Release date	March 22, 1965; 56 years ago (1965-03-22)
Introductory price	US$18,500, equivalent to about $151,900 in 2020
Units sold	50,000+
Platform	DEC 12-bit
Predecessor	PDP-5
Successor	PDP-12

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The earliest PDP-8 model, informally known as a “Straight-8”, was introduced on 22 March 1965 priced at $18,500[2] (equivalent to about $150,000 in 2020[3]). It used diode–transistor logic packaged on flip chip cards in a machine about the size of a small household refrigerator.^{[citation needed]} It was the first computer to be sold for under $20,000,[4] making it the best-selling computer in history at that time.[5]^{[failed verification]}[6]^{[failed verification]} The Straight-8 was supplanted in 1966 by the PDP-8/S, which was available in desktop and rack-mount models. Using a one-bit serialarithmetic logic unit (ALU) allowed the PDP-8/S to be smaller and less expensive, although slower than the original PDP-8. A basic 8/S sold for under $10,000, the first machine to reach that milestone.[4][7]

Later systems (the PDP-8/I and /L, the PDP-8/E, /F, and /M, and the PDP-8/A) returned to a faster, fully parallel implementation but use much less costly transistor–transistor logic (TTL) MSI logic. Most surviving PDP-8s are from this era. The PDP-8/E is common, and well-regarded because many types of I/O devices were available for it. The last commercial PDP-8 models introduced in 1979 are called “CMOS-8s”, based on CMOS microprocessors. They were not priced competitively, and the offering failed. Intersil sold the integrated circuits commercially through 1982 as the Intersil 6100 family. By virtue of their CMOS technology they had low power requirements and were used in some embedded military systems.

The chief engineer who designed the initial version of the PDP-8 was Edson de Castro, who later founded Data General.[8]

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. . . PDP-8 . . .