Terms and Conditions:

Henry M. Levy wrote:The book is now out of print and the copyright belongs to the author, who makes the material available here for viewing or downloading, in Adobe Acrobat PDF format (free Acrobat reader available here).

Book Excerpts:

The purpose of this book is to provide a single source of information about capability-based computer systems. Although capability systems have existed for nearly two decades (ed: this book was published in 1984), only recently have they appeared in architecture and operating sys tem textbooks. Much has been written about capability sys tems in the technical literature, but finding this information is often difficult.

This book is an introduction, a survey, a history, and an evaluation of capability, and object-based computer systems. It is intended for students, computer professionals, and computer-system designers. The book assumes a knowledge of the assembly-level architecture of at least one computer, an under standing of memory addressing and virtual memory systems, and some familiarity with operating systems. It can be used as a tutorial or reference text in advanced undergraduate or graduate courses in computer organization, computer architecture, or operating systems.

Each survey section presents the important features of a particular system. For this reason, different systems may be described at somewhat different levels. However, all systems are discussed in sufficient detail to give the reader an under standing of both the concepts and the low-level capability ad dressing and object-support mechanisms. An important goal of the book is examination of hardware and operating-system implementations of capabilities. Although all of the systems begin with a similar conceptual view of capabilities, the implementations are vastly different.