The x86 Microprocessors: 8086 to Pentium, Multicores, Atom and the 8051 Microcontroller, 2nd Edition

8

The Interrupt Structure of 8086

IN THIS CHAPTER, YOU WILL LEARN

• The concept of an interrupt.
• The interrupt response of the 8086.
• The way the interrupt vector table is organized for 8086.
• The idea of software interrupts.
• The operation of hardware interrupts of 8086.
• The significance of DOS and BIOS interrupts.
• How to access the video display by the use of BIOS interrupts.
• How to access the video display by direct writing/reading to the video RAM.
• How the PC’s keyboard and its controller are organized.
• How to use BIOS interrupts for keyboard access.
• The method of ‘hooking’ interrupts.
• How to write TSR programs.

Introduction

The word ‘interrupt’ brings to our mind many situations. It could be that we are at home doing something ...