DOS-15 Users Manual

This document describes the PDP-15 Disk Operating System (DOS-15), an integrated software system designed for research, engineering, and industrial environments. It covers the system's features, fundamental concepts, programming, and operational procedures.

The DOS-15 system is managed by a Monitor, which includes Resident, Nonresident, and System Loader components, providing capabilities for program flow, I/O handling, and system configuration. It supports various programming languages such as FORTRAN IV, FOCAL, and MACRO-15, along with utilities for program preparation, compilation, assembly, debugging, and execution. Key features include disk-resident software, interactive and conversational operation, dynamic storage and buffer allocation, and a flexible file structure that offers random and sequential access with multi-level file protection using User Identification Codes (UICs) and a Monitor Identification Code (MIC).

The manual details I/O communication through device-independent macros and handlers, elaborating on different data modes (IOPS ASCII, IOPS Binary, Image Alphanumeric, Image Binary, and Dump Mode) and logical record terminators. It also outlines system initialization procedures, including disk restoration (DOSSAV) and bootstrap loading. Comprehensive information is provided on keyboard commands for system control, requesting system information, managing file protection, allocating core, and saving/restoring core images. Additionally, the document describes the characteristics of various I/O device handlers, error detection, and recovery procedures, supporting both Page Mode and Bank Mode operations for memory addressability.