VIAUDD.SYS

VIA audio sound system driver for the VIA Southbridge with built in AC97 Controller. DEVICE=\MMOS2\VIAUDD.SYS


 * NOTE: There are different drivers with the same name available. Please consult the readme delivered with the driver.

Parameter
Refer to AC'97 specification for a list of register values and their meanings.
 * /N: - Symbolic device name for binding with MMPM/2. This is automatically selected by MINSTALL.EXE. Defaults to VIAUD1$".
 * /NO_IRQ_SHARING - Disable the IRQ sharing mode. Normally, VIAUDD.SYS automatically detects whether IRQ sharing is needed and performs the necessary setup.
 * /!OEM - Prevent any special setup for AC'97 codec ICs. This parameter disables any vendor-specific setup done by the driver.
 * /ALC|/!ALC - Override ALC-201A detection. Normally the driver detects the presence of ALC-201A automatically and performs the necessary setup; however, the presence of codec may be forced using /ALC or disabled with /!ALC (/!ALC is a synonym for /!OEM).
 * /LFREQ|/AFREQ /LFREQ, which is the default for chip revisions >=0x30, uses a modified frequency algorithm known from VIA drivers for Linux. /AFREQ, default for the older revisions, uses the officially documented algorithm known from ALSA driver. Use /LFREQ if the sound plays too slowly; use /AFREQ if the sound plays too fast or with interruptions.
 * /VERBOSE - Verbose output, useful for troubleshooting or finding out the capabilities of a specific AC'97 solution. Shows if any step during initialization fails and makes a pause to let the user examine the results.
 * /QUIET - Quiet initialization - display no messages at all.
 * /R: - Configure Audio Codec '97 registers manually. This is intended for advanced users, as the IOCTL90 mixer interface should be usually enough for customization. The format of is: =,,... or ..=value,...

Practical examples

 * Enable the +20 dB microphone gain: /R:0E=40
 * Enable simulated stereo (if supported): /R:20=4000
 * Enable bass boost (if supported): /R:20=1000