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From: tom@syssoft.com (Rodentia)
Newsgroups: comp.os.msdos.programmer,rec.games.programmer
Subject: Pulse Width Modulated Sound for PC's
Message-ID: <1990Dec20.171242.11369@syssoft.com>
Date: 20 Dec 90 17:12:42 GMT
Reply-To: tom@syssoft.com (Rodentia)
Organization: Systems & Software, Inc., Irvine, CA
Lines: 24

Programs such as Reply, Remac (both for DOS), and Sounder (for 
Windows) use pulse width modulation (PWM) about 6 bits deep at 
22KHz for high quality sound on the PC speaker.  Another package
commonly distributed as DIGITIZE.ARC, uses one bit deep sampling 
at about 16KHz.

A friend of a friend supposedly wrote some shareware program 
that include speech as a secondary feature.  He later received 
a letter from some company claiming a patent on some aspect of
the sound generation technology he was using.  I do not know 
if he used digitized sound exclusively or composed from 
text and/or phonemes.

My question is this:  Does anyone know of patents on either 
of the digital playback techniques described above?  I have
tried to track down the original FOAF, but he's in another
state, etc.  Please copy me e-mail on all replies as we've
just changed newsfeeds and I'm not confident that all news
is getting through.  Thank you.

-- 
Thomas Roden                            tom@syssoft.com
Systems and Software, Inc.              Voice:  (714) 833-1700 x454
                                        FAX:    (714) 833-1900