Need Code for Voice Board Digitizer

[Gil Kloepfer Jr.]

In article <1761 at ultb.isc.rit.edu> jeh at CS.rit.edu (J.E. Heliotis) writes:
>I have a student interested in doing Fourier Analysis on Data collected
>on a UNIX PC (7300/3B1) voice board.  I have the Applications Programmer
>kit and manuals, but they said that the A/D coding is proprietary.
>
>Is this really still true?  I will try some contacts at AT&T* if this
>fails.
>				Jim Heliotis
>				{allegra,seismo}!rochester!ritcv!jeh
>				jeh at CS.RIT.EDU

I've contacted *the* people at AT&T who know about such things, and yes,
indeed, it *is* proprietary.  They are not permitted to give out any
of the gut information about the internals of how the voice power system
works.

There is, however, an excellent reference about voice digitization in
general, which shows the 3B1 voice power system in block form.  This
is the AT&T Technical Journal, Sept/Oct 1986, Vol 65, issue 3.  The
journal says that back orders can be ordered by calling (800) 432-6000.
Warning-- This journal is FULL OF math equations describing digital
filters and the like that only someone who is well-versed in this
kind of thing will really understand.  The text of the journal is
techinically-oriented, but generally informative.

To be exact, by the way, the A/D coding is *not* the proprietary part
of the voice power system.  What is proprietary is the DSP used in the
compression of the sound (into sub-bands), the firmware on the board,
and the format used to store the sound on the 3B1.  The codec (which
is the part which does the conversion from various PCM forms to analog
and vice versa) has information available.

My apologies for any mistakes I may have made above (ie. no flames please).
I'm hoping that this information is at least 90% correct (as far as I
know it is), and that it will be a help to those of you who are curious
out there.

--------
| Gil Kloepfer, Jr.
| ICUS Software Systems/Bowne Management Systems (depending on where I am)
| ...ames!limbic!gil