v0.2 Rui Sousa <rsousa@grad.physics.sunysb.edu>

This serves to document the extensions/additions that
this driver makes to the documented OSS API.

Multiopen
------------------
It's possible to open /dev/dsp multiple times for reading
and writing.
This means:
1. several applications can use /dev/dsp simultaneously
   either using write() or mmap(). No modifications to
   the applications are required. 
2. you can do hardware mixing of several sounds.
   Just have your application open /dev/dsp as many
   times as sounds you want to mix (with different file
   descriptors) and then use normal write() calls or a
   mmap() mechanism for each one.
   You should also have a look at the SNDCTL_DSP_SETTRIGGER
   ioctl().
3. The driver supports three recording buffers that can be
   used simultaneuosly:
	AC97: 16 bit, stereo/mono, standart sampling rates.
	      The recording source is selected using DSP
	      microcode (see dsp.txt).

	MIC: 16 bit, mono, 8000Hz sampling rate.
	     The recording source is selected using DSP    
	     microcode (see dsp.txt).

	FX: 16 bit, up to 16 interleaved channels, 48000Hz sampling rate.
	    The source channels are selected by programming the
	    FXWC register.
	     
   If the recording source selected is the AC97 codec you can
   still use AC97 registers to select the analog input source.
	
