A Practical Introduction to Input and Output Ports

Abstract

This chapter discusses how microprocessors interact with devices. It takes the student from the basics of input and output, through the design of the interface between a processor and an external device, and concludes with a discussion of how to improve the performance of the I/O interface using interrupts. The PC parallel port is examined to give the student a chance to apply these concepts in hardware and software. Once the student has studied the material of this chapter and completed the hands-on experiments, they will be prepared to begin a study of how device drivers work within the context of an operating system.