Re: How is the IIgs beep generated?

[Mitchell Spector <mitch2gs@hotmail.com>]

"Michael J. Mahon" <mjmahon@aol.com> wrote:

>Mitchell Spector wrote:
>> "Michael J. Mahon" <mjmahon@aol.com> wrote:
>>     It's closer in pitch, but still not the very unique IIgs "bonk".
>> Using the different parameters (assuming I used them correctly)
>> got something closer, but still not exact.
>
>I had a IIgs and my //e side by side and put each into a loop
>doing the IIgs "native" bonk and my //e bonk about once a second.
>I adjusted the parameters to get the closest match, and it seemed
>right in pitch, duration, and envelope.

    Well, using a hardware IIGS.... immediately after doing the 'CALL 
768'  and listening, invoke the system bell with a CTRL-G. Do you 
hear how different the native bonk is? :)

    So I take it you cannot reproduce the IIGS bonk on an Apple II,
II+, IIe, IIc or IIc+ with 100% accuracy?

>>     I've seen speaker toggling used in native IIGS software for audio 
>> (e.g. Paperboy, Gauntlet, John Madden's Football) but is it just old
>> fashioned 8-bit Apple II sound. I wonder if some kind of simple music 
>> program could be written that could use it...just for the sake of
>> seeing if it could be done. The most simple thing to try would be 
>> to play any of the Control Panel bell pitches at will, like a piano 
>> keyboard! This would be running on a IIgs of course, we're talking
>> about just playing the pitches in the Sound Control Panel.
>
>Check out RT.SYNTH.  It doesn't (yet?) include a damped squarewave,
>but that would be a trivial addition--with any envelope.  (Of course,
>it's still 5-bit samples.)
>
>If a damped squarewave was all that was desired, then the native IIgs
>bonk routine approach (see Jerry's post) could be used, though it would
>take significant re-work to get accurate musical notes.

    I've played with RT.SYNTH on my 8-bit Apple II's, it amazes me
how far you can push the internal speaker!

    I was thinking of something unrelated though. The 15 pitches in 
the Sound Control Panel, they can only be played sequentially (+1 or
-1) in scale. I thought it'd be fun to program something where you
can play ANY of the 15 pitch tones at will (e.g. pitch 3, 8, 7, 15, 4).
Is there a way to access the Control Panel Sound's pitch and 
change it arbitrarily on the fly? Actually, I seem to remember this
is what the graphical Control Panel in System 6 allows, but I'd 
want to assign each pitch to a key press, much like RT.SYNTH.

    It's interesting how the IIGS bonk is completely reproduceable 
in an emulator, like KEGS (apart from a slight click or pop at the
end). If you look at how that is done, it would reveal any of the
mystery here.

Mitchell Spector