Early PC Audio Adapters

When the first audio adapters were introduced in the late 1980s by companies such as AdLib, Roland, and Creative Labs, they were aimed squarely at a gaming audience, were not compatible with each other, and often cost more than $100.

Note

About the same time as the release of the Creative Labs Game Blaster, hardware supporting the Musical Instrument Digital Interface (MIDI) became available for the PC. At this time, however, such hardware was used only in very specialized recording applications. As MIDI support became a more common feature in musical instruments, though, it also became a more affordable PC add-on.

The Game Blaster, which was compatible with only a handful of games, was soon replaced by the Sound Blaster, which was compatible with the AdLib sound card and the Creative Labs Game Blaster card, enabling it to support games that specified one sound card or the other. The Sound Blaster included a built-in microphone jack, stereo output, and a MIDI port for connecting the PC to a synthesizer or other electronic musical instrument. This established a baseline of features that would be supported by virtually all other sound cards and onboard sound features up to the present. Finally, the audio adapter had the potential for uses other than games. The follow-up Sound Blaster Pro featured improved sound when compared to the original Sound Blaster. The Sound Blaster Pro and its successors eventually triumphed over earlier rivals to become de facto standards for PC sound reproduction.

Note

Unlike de jure standards such as the IEEE-1394 port, which is an official standard of the IEEE organization, de facto standards are those that develop informally due to the widespread acceptance of the market leader's products in a particular segment of the marketplace. The Sound Blaster Pro is just one of many examples of a de facto standard: IBM's VGA card became a de facto baseline standard for video, and HP and Apple's different printer languages (HP PCL and Adobe PostScript) became de facto standards for printers.

Limitations of Sound Blaster Pro Compatibility

Through the mid-1990s, while MS-DOS was the standard gaming platform, many users of nonCreative Labs sound cards struggled with the limitations of their hardware's imperfect emulation of the Sound Blaster Pro. Unfortunately, some cards required two separate sets of hardware resources, using one set of IRQ, DMA, and I/O port addresses for native mode and a second set for Sound Blaster Pro compatibility. Others worked well within Windows or within an MS-DOS session running with Windows in the background but required the user to install a DOS-based Terminate and Stay Resident (TSR) driver program to work in MS-DOS itself.

However, the rise of 32-bit Windows games has made audio support very simple by comparison. Windows applications use the operating system's drivers to interface with hardware, relieving the software developer from needing to write different code for different sound cards, 3D graphics cards, and so on. For 3D sound and gaming graphics, Microsoft Windows uses a technology called DirectX, which was first introduced in December 1995; the current version is DirectX 9.0c.

DirectX and Audio Adapters

Microsoft's DirectX is a series of application program interfaces (APIs) that sit between multimedia applications and hardware. Unlike MS-DOS applications that required developers to develop direct hardware support for numerous models and brands of audio cards, video cards, and game controllers, Windows uses DirectX to "talk" to hardware in a more direct manner than normal Windows drivers do. This improves program performance and frees the software developer from the need to change the program to work with different devices. Instead, a game developer must work with only the DirectX sound engine, DirectX 3D renderer, and DirectX modem or network interface routines.

For more information about DirectX and sound hardware, see "3D Audio," p. 963.

Thanks to DirectX, sound card and chipset developers are assured that their products will work with recent and current versions of Windows. However, if you still enjoy playing MS-DOSbased games, current audio adapters, chipsets, and integrated audio solutions still might present a compatibility challenge to you because of fundamental hardware differences between the ISA expansion slots used by classic Creative Labs and other sound cards and PCI slots, chipsets, and integrated audio. The only way to ensure audio compatibility with these legacy programs is to use a Sound Blaster Procompatible ISA sound card (if you can obtain one) on a system running DOS 6.x, possibly with Windows 3.x as well, depending on the nature of the application.

For more information about using PCI sound hardware with MS-DOS games, see "Legacy (MS-DOS and Gameport) Game Support Issues," p. 953.