One of the less obvious functions of setcolor is to control
the sound of the bell that is usually built into the display or
keyboard. To change the bell tone, you must supply a pitch
and duration. Pitch is the period in microseconds,
and duration is measured in fifths of a second.
When using this option, a <Ctrl>G (bell) must be echoed to
the screen for the command to work. For example:
setcolor -p 500 2
This command sets the bell to a high pitch of short duration.
The higher the pitch number, the lower the sound generated.
This command sets the bell to a sustained low tone:
setcolor -p 7000 8
Note that each time <Ctrl>G is pressed, the bell will sound the tone most recently set.