Programmed Data Processor - 7 Reference Manual

This reference manual provides a comprehensive overview of the PDP-7, a solid-state, 18-bit binary computer designed for high-speed data processing in scientific, computing, and real-time control applications. The system features a 1.75-microsecond core memory, enabling a computation rate of 285,000 additions per second, and operates as a self-contained unit without special power or environmental requirements.

The basic PDP-7 configuration includes a central processor, operator console, 4096-word core memory, and a robust input/output (I/O) control system that supports parallel data transfer, program and data interrupts, and a real-time clock. Standard peripherals comprise a teleprinter, high-speed paper tape reader, and punch. The manual details optional expansions such as memory modules to increase capacity up to 32,768 words, an Extended Arithmetic Element (EAE) for high-speed multiplication, division, and shifting, and an Automatic Priority Interrupt system (Type 172) that handles multilevel interrupts across 16 channels.

The document extensively covers various optional I/O equipment, including mass storage solutions like DECtape, magnetic tape drives, and serial drums; diverse display systems such as CRT displays, light pens, and symbol generators; analog-to-digital converters; card readers and punches; and line printers. Each I/O device is described along with its specific I/O Transfer (IOT) instructions. Programming support includes an Assembler for symbolic language, a Digital Debugging Tape (DDT) system for program debugging, an Editor for source code modification, a FORTRAN Compiler, and BUS-PAK II for business-oriented data processing, all designed to streamline development. The manual concludes with appendices listing teleprinter codes, Hollerith codes, line printer codes, service practices, a RIM loader, and an instruction summary.