Speaker Response?

[cklipsch@universe.digex.net (Colin Klipsch)]

Greetings.  I have an obscure question about the Apple II's speaker
behavior.  (This would be the speaker found on the 8-bit Apple IIs, not
the //gs.)  I've searched through the on-line technical notes and was
unable to find the information I'm after.

I'd like to know the speaker "latency" -- the time it takes for the
diaphragm to move from one extreme to the other, after a reference to
a $C03x I/O address.  Let us assume that the diaphragm was already
resting at one extreme, and that no $C03x address is touched again
during the ensuing movement.

Perhaps this information is hidden in the Apple ][ Reference Manual that
I have, which talks about the speaker's voltages and impedances.  I'm
afraid I lack the "audiophile" knowledge necessary to comprehend what
these numbers are telling me.

Also, I notice that Electric Duet's music routine is touching the
speaker (via $C030) in intervals as small as 9 CPU cycles.  I know
Electric Duet accomplishes its magic by twiddling the speaker very
rapidly to put the speaker into more than its "ordinary" two states.
This suggests that the latency period is on the order of 9 cycles, or
perhaps much more?


Thanks for any help you can offer.

Colin K.
cklipsch@universe.digex.net