NAME
sb —
SoundBlaster family (and
compatible) audio device driver
SYNOPSIS
sb0 at isa? port 0x220 irq 5 drq 1 drq2 5
sb1 at isa? port 0x240 irq 7 drq 1 flags 1
sb* at isapnp?
sb* at pnpbios? index ?
audio* at audiobus?
midi* at sb?
mpu* at sb?
opl* at sb?
DESCRIPTION
The
sb driver provides support for the SoundBlaster,
SoundBlaster Pro, 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 use 1
flags specification 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.
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 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.
SoundBlaster 16 cards have MPU401 emulation and can use the mpu attachment,
older cards have a different way to generate MIDI and has a midi device
attached directly to the
sb.
SEE ALSO
aic(4),
audio(4),
isa(4),
isapnp(4),
joy(4),
midi(4),
mpu(4),
opl(4),
pnpbios(4)
HISTORY
The
sb device driver appeared in
NetBSD
1.0.
BUGS
Non-SCSI CD-ROM interfaces are not supported.
The MIDI interface on the SB hardware is braindead, and the driver needs to busy
wait while writing MIDI data. This will consume a lot of system time.