Real Mode and Protected Mode Architecture on Intel-Based Processors
Introduction
This site explores the way memory is referenced in real mode and protected and briefly discusses virtual 8086 mode. This site is designed
for the person who is already familiar with basic assembly programming and commonly used instructions who knows the semantics for accessing
memory but is confused about what segments mean and wishes to know more about the details underlining memory access.
Table of Contents
- Chapter 1 - Real mode architecture
Discusses in detail the way memory is addressed in real mode. For ordinary dos-based programs, this chapter should be the most helpful.
- Chapter 2 - Basic protected mode architecture
Discusses the basics on the way memory is addressed in protected mode (many of the details are beyond the scope of this site, check
our links page for more information). This chapter has limited use for windows-based programs, but is most
helpful if you want to design your own operating system and want a brief introduction to protected mode.
- Chapter 3 - Switching to protected mode
Discusses how to switch from real mode to protected mode (and back to real mode) and complications that may arise.
- Further Information
Copyright (©) 2003 by Eric Feiveson. All information in this site is provided as-is. Not responsible for typographical or other errors,
or complications that can arise from such errors. Windows is a registered trademark of the Microsoft Corporation. Any other copyrighted names in this site are
trademarks of their respective owners.