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Path: utzoo!mnetor!seismo!ll-xn!ames!amdahl!bnrmtv!perkins
From: perkins@bnrmtv.UUCP (Henry Perkins)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Request for program to turn PC speaker ON and OFF
Message-ID: <2069@bnrmtv.UUCP>
Date: Thu, 25-Jun-87 19:39:23 EDT
Article-I.D.: bnrmtv.2069
Posted: Thu Jun 25 19:39:23 1987
Date-Received: Sat, 27-Jun-87 05:36:12 EDT
References: <1279@crash.CTS.COM>
Organization: BNR Inc., Mountain View, California
Lines: 29
Keywords: Alternatives offered
Summary: This program isn't possible for a standard PC

While I agree that a program which would let you disable your
PC's speaker would be nice to have, it just isn't possible to
create.

A program causes sound to come out of the speaker by sending
bytes to an output port.  After that, a timer chip may keep
the sound going.  Apart from hardware solutions (stuffing
cotton in the speaker, for instance), all you could do is have
a program that would turn the speaker off every timer tick
(that's 18.2 times per second).  This isn't too difficult to
create, but won't work if programs disable interrupts while
they play with the speaker (more than likely, I'm afraid), and
you'd still get a little blip of sound before it is cut off.

The usual way of making a beep is to send a CTRL-G (ASCII bell
code) to the "Write TTY" interrupt function.  It IS possible
to ensure that these beeps don't occur.  I've made a program
which makes short beeps instead of the standard long ones, and
it would be trivial to have the program make no beep at all.

If anybody wants one or more of these programs, send me mail
and I'll be happy to provide them.  If I get enough responses,
I'll post them instead.  Please indicate if you can use
assembler source, or if you need a uuencoded .COM file.
-- 
{hplabs,amdahl,3comvax}!bnrmtv!perkins        --Henry Perkins

It is better never to have been born.  But who among us has such luck?
One in a million, perhaps.