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From: obryan@gumby.cc.wmich.edu (Mark O'Bryan)
Newsgroups: comp.sys.atari.st
Subject: Re: yamaha sound chip
Message-ID: <756@gumby.cc.wmich.edu>
Date: 12 Jun 89 17:37:45 GMT
References: <8906110020.AA01982@crash.cs.umass.edu>
Organization: Western Michigan University, Kalamazoo, MI
Lines: 21

In article <8906110020.AA01982@crash.cs.umass.edu>, FORSTER@cs.umass.EDU (David Forster) writes:
> Since you bring up the subject, does the chip also do something with incoming
> audio signals?  I noticed there's a pin for it on the monitor plug.  Is this
> actually connected?  (On the TI Explorer in my office, the audio chip not only
> generates sound, but also can be connected to a microphone to record sound, so
> this doesn't sound like such an unreasonable proposition.)

The audio input pin is designed for mixing an external input with the
internally generated 3 audio channels + noise.  The chip was designed
to be usable in a number of low-cost configurations, for various
purposes, and provided this feature as a free-bie.

There's no A-to-D converter inside that could be used to digitize the
incoming audio.  In fact, I don't think there's even a level comparator,
so you couldn't even do the A-D in software if you wanted to (and could
live with the slow speed).

-- 
Mark T. O'Bryan                 Internet:  obryan@gumby.cc.wmich.edu
Western Michigan University
Kalamazoo, MI  49008