Plays a tone on the PC speaker.
frequency input must be a number and is measured in hertz (cycles per second).
The larger the frequency the higher the pitch.
duration input must be a number and is measured in milliseconds.
The larger the duration the longer the tone plays for.
FMSLogo cannot respond to user control while it plays a tone.
TONE 1000 200
REPEAT 50 [ TONE REPCOUNT * 10 50 ]