Programmed Data Processor-8/S Users Handbook

Summary:

This handbook provides a comprehensive technical overview and operational guide for the Digital Equipment Corporation's (DEC) PDP-8/S, a small-scale, general-purpose computer. It serves as both a reference for the system’s architecture and a manual for its programming, operation, and peripheral interfacing.

The document covers the following key areas:

• System Overview and Architecture: Describes the PDP-8/S as a 12-bit, fixed-word length, serial computer featuring a 4096-word random-access magnetic core memory. It details the function of major internal registers, including the Accumulator (AC), Program Counter (PC), Memory Address Register (MA), and Memory Buffer (MB).
• Instruction Set: Provides a detailed breakdown of memory reference instructions (e.g., AND, TAD, ISZ, DCA, JMS, JMP) and augmented instructions (operate and I/O transfer). It includes descriptions of execution times, operational logic, and bit assignments.
• Programming: Details memory addressing methods (including indirect addressing and auto-indexing), logical and arithmetic operations, and the implementation of program interrupts.

• Input/Output (I/O) and Peripherals: Explains the PDP-8/S’s "bus" I/O system, which allows for the flexible connection of various external devices. Specific chapters detail the operation and programming of:

  • Teletype (Model 33 ASR)
  • High-Speed Perforated Tape Reader (PC02) and Punch (PC03)
  • Analog-to-Digital and Digital-to-Analog Converters
  • Incremental Plotters
  • Card Readers
  • Automatic Line Printers

• Operating Procedures: Offers guidance on using the operator console for manual data storage, modification, and machine control, as well as instructions for off-line Teletype operation.

• Appendices: Includes extensive reference material, such as complete instruction timing/codes, ASCII and card reader codes, octal-to-decimal conversion tables, and specific procedures for using RIM and Binary loaders.