Date: Thu, 13 Nov 1997 13:50:39 -0800 From: Julian Elischer <julian@whistle.com> To: "Chuck O'Donnell" <cao@bus.net> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: /dev/speaker Message-ID: <346B762F.41C67EA6@whistle.com> References: <Pine.BSF.3.96.971113125919.288A-100000@milf18.bus.net>
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Chuck O'Donnell wrote:
>
> Does anyone know a good way to beep the speaker from a CGI script?
>
> I found the 'pseudo-device speaker' in /sys/i386/conf/LINT, which uses the
> spkr.c driver to gain access through open("/dev/speaker", ...).
>
> Are there any other ways to access the computer speaker directly?
>
> I am not subscribed to this list so please send responses directly.
>
> Thank you.
>
> Chuck O'Donnell
define what you mean by "access the computer speaker directly"
the speaker is physically attached to the counter-timer chip.
you can program the counter to toggle the speaker at a known speed,
for a known period of time. or pulse once with a known pulse length.
That's about all.
of course htere are other tricks that can be achieved using this..
the pca device for example uses a high frequency (16kHz) carrier
which it modulates using PWM to produce a reasonable audio output.
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