Technical data

dbri(7D) Devices SunOS 5.5
NAME dbri − Dual Basic Rate ISDN and audio Interface
AVAILABILITY SPARC
The DBRI Multimedia Codec, and SpeakerBox are available on SPARCstation 10 and LX
systems.
SPARCstation 10SX and SPARCstation 20 systems have the Multimedia Codec integrated
onto the CPU board of the machine.
This hardware may or may not be available on future systems from Sun Microsystems
Computer Corporation.
There are new configurations for the SX10SX and Gypsy machines. The SS10BSX looks
like a speakerbox but does not have auto-detection of the Headphone and Microphone
ports. The Gypsy claims to be "onboard" but does have line in and line out ports.
DESCRIPTION The dbri device uses theT5900FC Dual Basic Rate ISDN Interface (DBRI) and Multimedia
Codec chips to implement the audio device interface. This interface is described fully in
the audio(7I) manual page.
Applications that open /dev/audio may use the AUDIO_GETDEV ioctl to determine
which audio device is beingused. The dbri driver will return the string"SUNW,dbri" in
the name field of the audio_device structure. The version field will contain "e" and the
config field will contain one of the following values:"isdn_b" on an ISDN B channel
stream, "speakerbox" on a /dev/audio stream associated with a SpeakerBox, and lastly
"onboard1" on a /dev/audio stream associated with the onboard Multimedia Codec.
The AUDIO_SETINFO ioctl controls device configuration parameters. When an applica-
tion modifies the record.buffer_sizefield using theAUDIO_SETINFO ioctl, the driver will
constrain it to be non-zero and a multiple of 16 bytes, up to a maximum of 8176 bytes.
Audio Interfaces The SpeakerBox audio peripheral is available for connection to the SpeakerBox Interface
(SBI) port of most dbri equipped systems and provides an integralmonaural speaker as
well as stereo line out, stereo linein, stereo headphone, and monaural microphone con-
nections. The headset output level is adequate to power most headphones, but may be
too low for some external speakers. Powered speakers or an external amplifier may be
used with both the headphone and line out ports.
SPARCstation LX systems have the Multimedia Codec integrated onto the CPU board of
the machine thus giving users the option of using it or using a SpeakerBox plugged into
the AUI/Audio port on the back panel. When usingthe "onboard" Codec, the micro-
phone and headphoneports are located on the system back panel - there are no Line In or
Line Out ports available for this configuration. In addition, the headphone and micro-
phone ports do not have the input detection circuitry to determine whether or not there is
currently headphones or a microphone plugged in. If a SpeakerBox is plugged in when
the machine is first rebooted and reconfigured, or upon the first access of the audio dev-
ice, it will be used, otherwise the onboard Codec will be used.
7D-72 modified 27 Feb 1995