Re: Apple II Speaker

[dalloff@gcfn.org (Dave Althoff Jr)]

Ned Ludd (spam@luddite.ca) wrote:
: Bill Garber <willy46pa@comcast.net> wrote:

: > Is there a place I can read the numeric
: > values of the signals being sent to the
: > A2 speaker? I know that it is being fed
: > pulses at different speeds to create the
: > pitch, but I need to be able to distinguish
: > one tone from another for a program I want
: > to write...

: You're working on voice recognition software, right?   ;-)

: If I understand what you're trying to do (which is doubtful), you might
: need to be looking at what's happening between speaker toggles. Hitting
: the speaker with any value makes it click once, so it is the delay in
: between clicks that determines the pitch. You'll have to have a look at
: your ML sound routine to figure out how the delay is generated.

Actually reading the speaker ($C030) clicks the speaker once, writing to
it clicks it twice.

Perhaps what you really want to do is to generate tones?  In that case,
there are many useful routines for doing that; I even have a routine
around here someplace that plays chords.

Or maybe you are trying to read audio input?  To do that you need to read
the cassette port (I forget the address...) and remember that the values
coming in are meaningless...it's a single-bit input and only the high-bit
matters for determining whether there is a signal there or not.  

--Dave Althoff, ][.
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