The PDP-11 is a series of 16-bit minicomputers sold by Digital Equipment Corporation (DEC) from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 was easier to program than its predecessors through the additional general-purpose registers. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years. In total, around 600,000 PDP-11s of all models were sold, making it one of DEC's most successful product lines. It was succeeded in the mid-range minicomputer niche by the 32-bit VAX-11.
Digital Equipment Corporation, also known as DEC and using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. It was a leading vendor of computer systems, including computers, software, and peripherals, and its PDP and successor VAX products were the most successful of all minicomputers in terms of sales.