PDP-9/L User Handbook

This document is a user handbook for the PDP-9/L programmed data processing system, published in June 1968. It provides a comprehensive overview of the computer's architecture, software, peripherals, and operational considerations.

The PDP-9/L is a general-purpose, 18-bit, fixed-word length, parallel binary computer featuring high performance, reliability, and easy input/output interfacing, built with FLIP CHIP hybrid integrated circuits. Its core memory has a 1.5 microsecond cycle time and a minimum configuration of 4096 words, expandable to 32,768 words. Key hardware features include direct and indirect addressing, autoindexing, optional Extended Arithmetic Element (EAE) for fast arithmetic, power failure protection, and memory protection.

The software system is divided into PDP-9/L COMPACT (for paper tape environments, including Assembler, Symbolic Editor, Debugging tools like ODT-9 and TRACE-9, and utility programs) and PDP-9 ADVANCED (a relocatable system supporting FORTRAN IV, Macro Assembler, sophisticated debugging, and a device-independent Input/Output Programming System (IOPS), leveraging bulk storage like DECtape, magnetic tape, or disk). Diagnostic programs (MAINDEC) are also provided for hardware troubleshooting.

The document details standard and optional peripherals, including Teletype Model ASR-33, high-speed paper tape reader/punch, card readers, line printers, incremental plotters, oscilloscope displays, light pens, analog-to-digital and digital-to-analog converters, multi-station Teletype controls, relay buffers, interprocessor buffers, and data communications systems.

It explains system organization, addressing modes, instruction sets (memory reference, augmented, I/O transfer, EAE), data formats, and arithmetic information (signed data notations, scaling for fixed-point arithmetic). Input/output operations are covered in detail, including program-controlled transfers, data channel transfers, the I/O skip facility, I/O read status, program interrupt, automatic priority interrupt (API), dynamic priority reallocation, and real-time clock functions.

Finally, the handbook describes the operator console and marginal check panel controls and indicators, provides an introduction to interfacing using Digital's FLIP CHIP modules, details the I/O bus structure and signals, and offers guidance on installation planning, including physical dimensions, power, and cabling requirements for various system configurations.