David Condon wrote:
> 
> I think more audio support would be a really interesting thing to add to
> NetBSD/Mac. 

Me too, I'm just about finished translating the Quadra 700 .Sound driver
into something resembling C so that I can see what's going on.

> I was just doing some exploring through the process of generating
> the beep. In ite.c we see that asc_ring_bell() is being called with a
> bell_freq of 1880. The tone that is actually coming out (for me, at least)
> is somewhere between the E and F above A 440, i.e. about 675 Hz. And the
> duration is 10 -- 10 of what unit?

All good questions.  What kind of machine do you have?  This will
definitely affect what kind of sound you hear.  I think that the current
asc driver really only supports the ASC, not the EASC.  At least my Quadra
only clicks, instead of beeping like it should.  I think I've gotten this
figured out, but I'm not 100% positive yet.  As for the answers to your
questions, it kinda depends on what kind of machine Brad Grantham
developed the original ASC support.  The sampling rate can vary depending
on how you program it, and the number of buffers you use varies as well.
I'm still not entirely sure how the whole duration thing works on the
whole, either, since increasing the duration on my machine doesn't turn a
click into a beep.

I'll probably have a survey (a quick C program) for people to try in a
couple of days that might give me a little more info on how this stuff
works.

Later.

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
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I speak only on my own behalf, not for my employer.