The 12-bit PDP-8 was the first successful commercial minicomputer, produced by Digital Equipment Corporation (DEC) in the 1960s. DEC introduced it on 22 March 1965, and sold more than 50,000 systems, the most of any computer up to that date. It was the first widely sold computer in the DEC PDP series of computers (the PDP-5 was not originally intended to be a general-purpose computer). The chief engineer who designed the initial version of the PDP-8 was Edson de Castro, who later founded Data General.
The earliest PDP-8 model (informally known as a "Straight-8") used diode-transistor logic, packaged on flip chip cards, and was about the size of a minibar-fridge.
This was followed by the PDP-8/S, a desktop model. By using a one-bit serial ALU implementation, the PDP-8/S was smaller, less expensive, but vastly slower than the original PDP-8.
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 used much less-expensive TTL MSI logic. Most surviving PDP-8s are from this era. The PDP-8/E is common, and well-regarded because so many types of I/O devices were available for it. It was often configured as a general-purpose computer.
In 1975, early personal computers based on inexpensive microprocessors, such as the MITS Altair and later TRS-80, Apple II and others began to dominate the market for small general purpose computers.
The last commercial PDP-8 models in 1979 were called "CMOS-8s" and used custom CMOS microprocessors. They were not priced competitively, and the offering failed. The IBM PC in 1981 cemented the doom of the CMOS-8s by making a legitimate, well-supported small microprocessor computer.
Intersil sold the integrated circuits commercially through to 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.
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