mavb
—
Moosehead A/V Board audio device
mavb0 at mace0 offset 0x300000 intr 6
audio* at audiobus?
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.
The mavb
driver first appeared in
OpenBSD 3.7. It was later ported to
NetBSD 5.0.
The mavb
driver was written by Mark Kettenis, and ported
to NetBSD by Jared D. McNeill.
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.
Currently only sample rates up to 48 kHz are supported. Recording is not
implemented yet. The second DAC on the AD1843 codec sits idle.