Preface

The UOS Internals Manual provides developers and maintenance programmers with a comprehensive technical overview of UOS. The manual presents the philosophy, functionality and structure of UOS.

The data structures presented herein are shown using Pascal syntax, but they are not inherent to the Pascal programming language. All structures are "packed", meaning that items are aligned on byte boundaries. For clarity, the data types used in these structures are defined as follows:

Type	Description
byte	unsigned 8-bit integer
word	unsigned 16-bit integer
longint	signed 32-bit 2's complement integer
cardinal	unsigned 32-bit integer
int64	signed 64-bit 2's complement integer
pchar	pointer to text
pointer	generic pointer
string[n]	A byte length, followed by an array of characters that is n characters in length. Unused characters are set to 0.

Note that the size of pointers is platform dependent.

This document is divided into several sections, each dealing with a functionally separate aspect of UOS.

Part I: Overview

Part II: Terminal Services

Part III: The UOS File System

Part IV: System Initialization