> Voila...

> Dave

I've had a go at your circuit and operation (always in
the market for more noise)

http://home.clear.net.nz/pages/joecolquitt/davedong.html

but it doesna seem to work as you described. What you
get is a continuous tone for 1 second. No decay ;-(((

The traces show the ~ 1kHz PIC output and the signal to the
audio amp

OK (if shorter) for a keyboard beep though

Any ideas for a fixit ? A diode or two ?

PS, based on TMR0 IRQ, no good for 12C users, sorry

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