The Sound Blaster family of sound cards was the de facto standard for consumer audio on the IBM PC compatible system platform, until the widespread transition to Microsoft Windows 95, which standardized the programming interface at application level (eliminating the importance of backward compatibility with Soundblaster), and the evolution in PC design led to onboard motherboard-audio, which commoditized PC audio functionality.

A sound card (also known as an audio card) is a computer expansion card that facilitates the input and output of audio signals to and from a computer under control of computer programs. Typical uses of sound cards include providing the audio component for multimedia applications such as music composition, editing video or audio, presentation, education, and entertainment (games). Many computers have sound capabilities built in, while others require additional expansion cards to provide for audio capability.

(Audio Codec'97) A specification for building audio and modem functions on a PC motherboard. Introduced in 1996 by Intel, AC'97 provides 20-bit, 48 kHz audio with six channels (5.1). It supports one audio stream per system and a two element array microphone.

A  very popular family of sound cards from Creative Labs. In the days of DOS, Sound Blaster was the de facto interface for gaming sounds. Monaural Sound Blaster cards were introduced in 1989, and stereo cards followed in 1992 (Sound Blaster Pro). Wavetable MIDI was added with the 16-bit Sound Blaster AWE32 and AWE64 with 32 and 64 voices. In 1998, Sound Blaster Live was the first PCI-based sound card. Over the years, the Sound Blaster line has been greatly enhanced to provide 3D audio and home theater quality sound directly from a PC. See Creative Labs, DirectSound and OpenAL.

Introduction to How Sound Cards Work

­Before the invention of the sound card, a PC could make one sound - a beep. Although the computer could change the beep's frequency and duration, it couldn't change the volume or create other sounds.

At first, the beep acted primarily as a signal or a warning. Later, developers created music for the earliest PC games using beeps of different pitches and lengths. This music was not particularly realistic -- you can hear samples from some of these soundtracks at Crossfire Designs.

When CDs were first introduced in the early 1980s, their single purpose in life was to hold music in a digital format. In order to understand how a CD works, you need to first understand how digital recording and playback works and the difference between analog and digital technologies.

In this article, we will examine analog and digital recording so that you have a complete understanding of the difference between the two techniques

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Quality of Service (QoS) are mechanisms for controlling the performance, reliability and usability of a telecommunications service. Mobile cellular service providers may offer mobile QoS to customers just as the fixed line PSTN services providers and Internet Service Provides (ISP) may offer QoS. QoS mechanisms are always provided for circuit switched services, and are essential for non-elastic services, for example streaming multimedia. It is also essential in networks dominated by such services, which is the case in today's mobile communication networks, but not necessarily tomorrow.

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The term pro forma (Latin "as a matter of form") is a term applied to practices or documents that are done as a pure formality, perfunctory, or seek to satisfy the minimum requirements or to conform to a convention or doctrine. It has different meanings in different fields.

For example, country A does not require person X to have a visa before entering the country but person X is in country B which requires a visa from country A in order to allow X to depart. In that case country A may issue a pro-forma visa to X, meaning the only object of the visa is to satisfy the formal requirement for X to have a visa and not any real requirement by country A.