NAME
mavb —
Moosehead A/V Board audio
device
SYNOPSIS
mavb0 at mace0 offset 0x300000 intr 6
audio* at audiobus?
DESCRIPTION
The
mavb driver provides support for the Moosehead A/V Board
found on SGI O2 machines.
The Moosehead A/V Board uses an AD1843 codec that supports 8- and 16-bit audio
sample recording and playback at rates from 5 to 54 kHz, with 1 Hz resolution.
The
mavb driver also makes it possible to control the
playback volume by using the buttons on the front of the O2.
SEE ALSO
audio(4),
sgimips/intro(4),
sgimips/mace(4)
HISTORY
The
mavb driver first appeared in
OpenBSD
3.7. It was later ported to
NetBSD 5.0.
AUTHORS
The
mavb driver was written by Mark Kettenis, and ported to
NetBSD by Jared D. McNeill.
CAVEATS
The analog mixer in the AD1843 codec does not provide a master volume control.
Therefore, the O2 volume buttons only control the output volume of the DAC.
BUGS
Currently only sample rates up to 48 kHz are supported. Recording is not
implemented yet. The second DAC on the AD1843 codec sits idle.