01 introToSoftware

This document is the DECsystem-10 User's Handbook, Second Edition (July 1972), providing an introduction to the DECsystem-10 computer system.

It outlines the system's three main components:

1. Hardware: A family of expandable computer systems (e.g., DECsystem-1040 to 1077) built around one or two PDP-10 central processors, featuring various core memories, disk and drum storage, magnetic tape systems, and input/output devices like card readers, printers, plotters, teletypes, and data communication systems.
2. Resident Operating System (Monitor): This continuously running software acts as an intermediary between users and hardware, managing resources and concurrent operations. Its key routines include:
   • Command Decoder: Interprets user commands.
   • Scheduler: Decides which jobs run, allocates resources, and manages job priorities.
   • Swapper: Moves user programs between core memory and secondary storage for efficient utilization.
   • UUO Handler: Processes user program requests for operating system services.
   • Input/Output Routines: Directs data transfers between devices and user programs.
   • File Handler: Manages named files, directories, access protection, and dynamic storage allocation.
3. Non-Resident Software: Programs loaded from mass storage as needed, providing tools for users. This includes:
   • Translators: MACRO (assembler), ALGOL, BASIC, COBOL, and FORTRAN (compilers), and AID (an interactive interpreter).
   • Editors: LINED (line editor) and TECO (a powerful character-oriented text editor).
   • Utilities: SOUP (Software Updating Package), RUNOFF (manuscript formatting), CREF (cross-reference lister), DDT (Dynamic Debugging Technique for on-line debugging), FILEX (file transfer and conversion), LOADER (for program loading and linking), and PIP (Peripheral Interchange Program for file manipulation).

The handbook emphasizes the DECsystem-10's multimode computing capabilities, supporting concurrent timesharing (interactive multi-user access, file sharing, spooling, memory protection), multiprogram batch (executing multiple jobs concurrently, flexible input/output), real-time operations (fast response, job locking, high-priority queues, inter-job communication), and remote communications (allowing distant users to access central resources and peripherals).

A comprehensive glossary of terms is also provided. The document aims to be a foundational guide for users before delving into more detailed manuals, highlighting the system's flexibility, power, and user-friendly design.