How do I ring a bell?

Frank Leonhardt frank2 at
Mon Oct 7 20:09:46 UTC 2013

On 07/10/2013 13:36, Polytropon wrote:
> > Is there any way to make a noise through the built in "bell" speaker
> > found on an IBM PC compatible server box? Writing 007 to the BIOS cout
> > routine might do it, but I've realised I haven't got a clue how to 
> do that.
 > Making it audible is part of the local terminal emulator,
 > either the TTY (text mode) driver or via xterm (or the
 > preferred alternative terminal emulator in X).

Yers, but I'm not running X. Or a character terminal come to that :-)

 > A more sophisticated interface is provided as soon as your
 > kernel has
 >     device speaker
 > compiled in (or speaker.ko has been loaded). Now you can
 > play wonderful music through the speaker. :-)
 > See "man 4 speaker" for details.

Thanks! This is what I was looking for.

 > See the following shell script as an example of what you
 > can do: <snip>

Overkill. I have proper work to do rather than working out how to play 
appropriate bit silly little tunes for every eventuality. Actually 
spkr.c has some useful comments in it - apparently it works the same as 
IBM PC BASIC. Now how do I make it polyphonic...

 > Always make sure that the system actually _has_ got an
 > internal speaker! I assume that modern PC hardware could
 > have it removed along with floppy drive connector, parallel
 > port or power switch.

Remains to be seen, but most still seem to have one so the BIOS ROM can 
make "beep" diagnostic codes if it can't do anything else.

 >> P.S. "cdcontrol -f /dev/mycdrom eject" is the best I've come up with so
 >> far for getting attention.
 > That's a really clever idea, never heared of that. It has
 > the advantage of being permanent because the drive will
 > stay open when the sound of its motor has finished. :-)

I use it all the time, especially when directing a tech to the 
appropriate server in a rack. "It's the one I just popped the CD drive 
on". These days servers have the spring-loaded notebook drives instead 
of the motorised trays, which is a pity. You could keep winding the 
motorised ones in and out until someone spotted it. I suppose if you did 
it energetically enough it might catch fire and set off the smoke alarm 
(audible). Or leave it wound out with a tin can balanced on it; to make 
a noise wind it back in and hear it clatter to the floor.

(Incidentally - email over-lap because earlier reply posted to me and 
list rather than just list)

Regards, Frank.

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