This is a little thing I wrote that simulates a telephone ring via the Linux console.  The underlying console is used so that it can be used for Tcl and/or Tk.

I'd rather that this work via an open'ed FD on /dev/console but I can't seem to get that to work. It will ring ok, but doesn't change the frequency as it does via echo.  But it does open a door to a lot of simple sound possibilities via the PC speaker, and without any extensions.  Alarm clocks, fancy alerts, whatever...

 # ring proc by Mike Tuxford
 proc ring {} {
   #                       duration (ms)
   exec /bin/echo -e '\\33\[11\;40]' > /dev/console
   for {set i 0} {$i < 8} {incr i} {
     #                       freq. (HZ)
     exec /bin/echo -e '\\33\[10\;770]' > /dev/console
     exec /bin/echo -e '\\a' > /dev/console
     after 40
     exec /bin/echo -e '\\33\[10\;870]' > /dev/console
     exec /bin/echo -e '\\a' > /dev/console
     if {$i == 3} {
       after 200
     } else {
       after 40
     }
   }
   # From the kernel console.c
   # Here is the default bell parameters: 750HZ, 1/8th of a second
   # reset the defaults
   exec /bin/echo -e '\\33\[10\;750\]\\33\[11\;125\]' > /dev/console
   return
 }
 ring