From owner-freebsd-hackers  Thu Nov 13 14:01:24 1997
Return-Path: <owner-freebsd-hackers>
Received: (from root@localhost)
          by hub.freebsd.org (8.8.7/8.8.7) id OAA25917
          for hackers-outgoing; Thu, 13 Nov 1997 14:01:24 -0800 (PST)
          (envelope-from owner-freebsd-hackers)
Received: from alpo.whistle.com (alpo.whistle.com [207.76.204.38])
          by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id OAA25904
          for <freebsd-hackers@FreeBSD.ORG>; Thu, 13 Nov 1997 14:01:18 -0800 (PST)
          (envelope-from julian@whistle.com)
Received: (from daemon@localhost)
	by alpo.whistle.com (8.8.5/8.8.5) id NAA19493;
	Thu, 13 Nov 1997 13:52:44 -0800 (PST)
Received: from UNKNOWN(), claiming to be "current1.whistle.com"
 via SMTP by alpo.whistle.com, id smtpd019486; Thu Nov 13 13:52:36 1997
Message-ID: <346B762F.41C67EA6@whistle.com>
Date: Thu, 13 Nov 1997 13:50:39 -0800
From: Julian Elischer <julian@whistle.com>
Organization: Whistle Communications
X-Mailer: Mozilla 3.0Gold (X11; I; FreeBSD 2.2-CURRENT i386)
MIME-Version: 1.0
To: "Chuck O'Donnell" <cao@bus.net>
CC: freebsd-hackers@FreeBSD.ORG
Subject: Re: /dev/speaker
References: <Pine.BSF.3.96.971113125919.288A-100000@milf18.bus.net>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: owner-freebsd-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

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.