uVision2 Simulator

I am using the following code in the function editor.
It was copied from the Kiel "Getting Started with UVision2" manual pg 113.

it seems to work but does not quit when SIGNAL KILL is typed
on the command line.
Does anyone know how to use the SIGNAL KILL command?

signal void serial_input (void)
{
while (1)
{
// twatch (1000000) // delay 1,000,000 CPU cycles to let user program run
twatch(CLOCK);
S0IN = 'A';
twatch (CLOCK / 900);
S0IN = 'B';
twatch (CLOCK / 900);
S0IN = 'C';
}
}