Programmed Data Processor (PDP), referred to by some customers, media and authors as "Programmable Data Processor,"[1][2][3] is a term used by the Digital Equipment Corporation from 1957 to 1990 for several lines of minicomputers.[4]
The name 'PDP' intentionally avoids the use of the term 'computer'. At the time of the first PDPs, computers had a reputation of being large, complicated, and expensive machines. The venture capitalists behind Digital (especially Georges Doriot) would not support Digital's attempting to build a 'computer' and the term 'minicomputer' had not yet been coined.[5][6] So instead, Digital used their existing line of logic modules to build a Programmed Data Processor and aimed it at a market that could not afford the larger computers.
The various PDP machines can generally be grouped into families based on word length.