Recording
---------

Recording does not work on the author's card, but there
is at least one report of it working on later silicon.
The chip behaves differently than described in the data sheet,
likely due to a chip bug. Working around this would require
the help of ESS (for example by publishing an errata sheet),
but ESS has not done so so far.

Also, the chip only supports 24 bit addresses for recording,
which means it cannot work on some Alpha mainboards.


/proc/sound, /dev/sndstat
-------------------------

/proc/sound and /dev/sndstat is not supported by the
driver. To find out whether the driver succeeded loading,
check the kernel log (dmesg).


ALaw/uLaw sample formats
------------------------

This driver does not support the ALaw/uLaw sample formats.
ALaw is the default mode when opening a sound device
using OSS/Free. The reason for the lack of support is
that the hardware does not support these formats, and adding
conversion routines to the kernel would lead to very ugly
code in the presence of the mmap interface to the driver.
And since xquake uses mmap, mmap is considered important :-)
and no sane application uses ALaw/uLaw these days anyway.
In short, playing a Sun .au file as follows:

cat my_file.au > /dev/dsp

does not work. Instead, you may use the play script from
Chris Bagwell's sox-12.14 package (or later, available from the URL
below) to play many different audio file formats.
The script automatically determines the audio format
and does do audio conversions if necessary.
http://home.sprynet.com/sprynet/cbagwell/projects.html


Blocking vs. nonblocking IO
---------------------------

Unlike OSS/Free this driver honours the O_NONBLOCK file flag
not only during open, but also during read and write.
This is an effort to make the sound driver interface more
regular. Timidity has problems with this; a patch
is available from http://www.ife.ee.ethz.ch/~sailer/linux/pciaudio.html.
(Timidity patched will also run on OSS/Free).


MIDI UART
---------

The driver supports a simple MIDI UART interface, with
no ioctl's supported.


MIDI synthesizer
----------------

The card has an OPL compatible FM synthesizer.

Thomas Sailer
t.sailer@alumni.ethz.ch