From alsa-devel-owner@alsa.jcu.cz  Thu Dec 24 23:33:25 1998
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To: alsa-devel@alsa.jcu.cz
Subject: ALSA 0.2.0-pre10p2 weirdness on Diamond Sonic Sound LX (Opti 82C928)
From: amu@mit.edu (Aaron M. Ucko)
Date: 24 Dec 1998 16:28:57 -0600
Message-ID: <udlu2yltbrq.fsf@kepler.x>
Reply-To: alsa-devel@alsa.jcu.cz
Sender: alsa-devel-owner@alsa.jcu.cz
Precedence: list

I decided to try running ALSA on my machine at home, which has an
obscure old ISA sound card, a Diamond SonicSound LX.  This card is
controlled by an Opti 82C928 chip and has an OPL3 and an AD1848 to
deal with actual sound production.  Since the '928 is almost identical
to the Oak Mozart chip, I tried using the Mozart driver, which didn't
want to load because the '928 fails the

	snd_mozart_read(3) & 0x03) != 0x03

test.  When I commented that code out, the module loaded happily.

However, I'm getting terrible sound quality; even using the native
interface, I hear clicks before playback, and the actual data sounds
really distorted.  (I'm not quite sure how to describe the distortion.
Sinusoids at frequencies which divide whatever sampling rate I'm using
come out at lower frequencies, at least for monophonic 8-bit signals.
Sinusoids at other frequencies, including neighboring frequencies,
just sound terrible.  When I run Osstest's "rising tone" test, I hear
a lower-pitched tone which alternately rises and falls on top of the
main rising tone.)

Other info:  I'm using Linux 2.0.36.  OSS does not have these problems
with my card.

I should have plenty of time to test fixes in the next few days, but
after that I'll be away from this machine for at least three months,
so I'd appreciate quick replies.

BTW, sorry about the mail to alsa-user...I realized a moment too late
that I'd accidentally left out -request.

