Programmed Data Processor-7 (PDP-7)

This document describes the PDP-7, a general-purpose, solid-state digital computer developed by Digital Equipment Corporation in 1964. Designed for high-speed data handling in scientific laboratories, computing centers, and real-time process control systems, the PDP-7 features an 18-bit word length, 1's and 2's complement arithmetic, and a random access magnetic core memory with a 1.75 microsecond cycle time, achieving 285,000 additions per second.

Key features include the use of integrated FLIP CHIP modules for low cost and high reliability, a modular design facilitating peripheral expansion, and fully parallel internal operations for simplified maintenance. The system comes with comprehensive I/O control for up to 64 devices, including program and data interrupts, I/O trap for time-shared systems, and a real-time clock. Software support includes an advanced FORTRAN compiler, symbolic assembler, editor, and debugging system. Memory is expandable from a basic 4096 words up to 32,768 words, and optional features like an Extended Arithmetic Element (EAE) and Automatic Priority Interrupt (16 channels) enhance performance and I/O handling. The document also details the instruction set (memory reference, operate, and IOT instructions) and a wide array of input/output options such as drum systems, various CRT displays, light pens, plotters, card readers/punches, line printers, magnetic tape and DECtape systems, and analog-to-digital/digital-to-analog converters. The PDP-7 is engineered for high reliability, including thorough testing and built-in marginal test capabilities.