Programmed Data Processor

Series of computers made by Digitial Equipment Corporation. PDP is an abbreviation for Programmable Data Processor -- they were given that name because at the time of their introduction computers had a reputation of being large and expensive machines, and the PDP was aimed at a market who couldn't afford them.

Some of the PDP machines are related to each other; but most have little more in common than having been made by the same company.

Members of the PDP series include:

• PDP-1: the original PDP

• PDP-6: timesharing machine (was it 18 or 36 bits?)

• PDP-8: 6-bit machine. The first "personal computer".

• PDP-9: ???

• PDP-10: 36-bit timesharing machine. Descendant of PDP-6.

• PDP-11: 16-bit machine. The VAX series was descended from it.

The PDP-8 and PDP-11 were the most popular of the PDP series of machines.