SB(4) - Device Drivers Manual (i386) #

SB(4) - Device Drivers Manual (i386)

NAME #

sb - SoundBlaster family audio device

SYNOPSIS #

sb0 at isa? port 0x220 irq 5 drq 1 sb1 at isa? port 0x240 irq 7 drq 1 flags 1 sb* at isapnp? audio* at sb? midi* at sb? (MPU401 port)

DESCRIPTION #

The sb driver supports the SoundBlaster 16, Jazz 16, SoundBlaster AWE 32, SoundBlaster AWE 64, and hardware register-level compatible audio cards.

The SoundBlaster series are half-duplex cards, capable of 8- and 16-bit audio sample recording and playback at rates up to 44.1kHz (depending on the particular model).

The base I/O port address is usually jumper-selected to either 0x220 or 0x240 (newer cards may provide software configuration, but this driver does not directly support them–you must configure the card for its I/O addresses with other software). The SoundBlaster takes 16 I/O ports. For the SoundBlaster and SoundBlaster Pro, the IRQ and DRQ channels are jumper-selected. For the SoundBlaster 16, the IRQ and DRQ channels are set by this driver to the values specified in the config file. The IRQ must be selected from the set {5,7,9,10}.

The configuration file must set the value of flags to 1 to enable the Jazz16 support. This is to avoid potential conflicts with other devices when probing the Jazz 16 because it requires use of extra I/O ports not in the base port range.

The joystick interface (if enabled by a jumper) is handled by the joy(4) driver, and the optional SCSI CD-ROM interface is handled by the aic(4) driver.

HISTORY #

The sb device driver appeared in NetBSD 1.0.

BUGS #

With a SoundBlaster 16 card the device is full duplex, but it can only sensibly handle a precision of 8 bits. It does so by extending the output 8 bit samples to 16 bits and using the 8 bit DMA channel for input and the 16 bit channel for output.

The non-SCSI CD-ROM interfaces found on some older cards are not supported.

OpenBSD 7.5 - August 31, 2016