Chapter 14. Audio Hardware

Since the first edition of this book was published in 1988, a lot has happened to audio hardware. Although rudimentary audio capabilities were part of the original IBM PC of 1981 and its many successors, audio was used on early computers for troubleshooting rather than for creative tasks. Computers used beeps for little other than to signal problems such as a full keyboard buffer or errors during the power on self test (POST) sequence. The Macintosh, first introduced in 1984, included high-quality audio capabilities in its built-in hardware, but PCs did not gain comparable audio capabilities until the first add-on sound cards from companies such as Ad Lib and Creative Labs were developed in the late 1980s.

Thanks to competition among many companies, we now enjoy widely supported d e facto hardware and software standards for audio. Audio hardware has gone from being an expensive, exotic add-on to being an assumed part of virtually any system configuration.

Today's PC audio hardware might take one of the following forms:

• An audio adapter on a PCI expansion card that you install into a bus slot in the computer.

• An AC'97 sound codec chip located on the motherboard, using sound chips from companies such as Crystal, Analog Devices, Sigmatel, ESS, or others.

• Hardware that's integrated into the motherboard's main chipset. Intel, SiS, NVIDIA, Aopen, and VIA have all released products in this category at one point or another.

Regardless of their location, the audio features use jacks for speakers and a microphone. In addition, many of them provide dedicated jacks for MIDI hardware (older cards usually provided an analog game port for joysticks). As you will see later in this chapter, many mid-range and high-end audio adapters also support sophisticated digital audio input and output. On the software side, the audio adapter requires the support of a driver that you install either directly from an application or in your computer's operating system. This chapter focuses on the audio products found in today's PCs, their uses, and how you install and operate them.