PDP-11 Rides on a Unibus

This document describes the PDP-11, a new 16-bit minicomputer from Digital Equipment Corp. (DEC). It highlights the PDP-11's modular architecture, centered around a "Unibus" that allows direct communication between system components without intervention from the central processor. The article details the machine's processing capabilities, memory options (including read-only and read-write core), and interrupt handling. It also discusses the PDP-11's innovative addressing modes and double-operand instructions, which contribute to its efficiency. Two initial configurations are presented: the PDP-11/10 for dedicated controllers and the PDP-11/20, a more general-purpose system. The document suggests that the PDP-11's architecture represents a new design philosophy for DEC's future machines, emphasizing modularity and flexibility for easy upgrades.