.\"	$NetBSD: esa.4,v 1.11 2014/03/18 18:20:39 riastradh Exp $
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.\" Copyright (c) 2001, 2002 Jared D. McNeill <jmcneill@invisible.ca>
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.Dd May 13, 2008
.Dt ESA 4
.Os
.Sh NAME
.Nm esa
.Nd ESS Technology Allegro-1 / Maestro-3 family audio device driver
.Sh SYNOPSIS
.Cd "esa*   at pci? dev ? function ?"
.Cd "audio* at audiobus?"
.Cd "options ESA_NUM_VOICES=4"
.Sh DESCRIPTION
The
.Nm
driver provides support for the ESS Allegro-1 and Maestro-3 audio devices
on the PCI bus.
These devices are popular in laptop systems.
.Pp
The Allegro-1 and the Maestro-3 are full-duplex devices that allow
independent playback and recording at sample rates between 8000Hz and
48000Hz and are capable of playback at 8 and 16 bit in mono and stereo.
.Pp
Setting options ESA_NUM_VOICES=4 allows for hardware mixing in the device
driver.
Note that due to microcode constraints, the
.Nm
driver is currently limited to 4 simultaneous voices.
.Sh SEE ALSO
.Xr ac97 4 ,
.Xr audio 4 ,
.Xr pci 4
.Sh HISTORY
The
.Nm
device driver appeared in
.Nx 1.5.3 .
.Sh AUTHORS
.An Jared D. McNeill Aq Mt jmcneill@invisible.ca