 BEEP.EXE - by Alessandro Cantatore - 2003 Italy

 BEEP.EXE plays iteratively a sequence of sounds of constant or
 variable duration via the PC loudspeaker.
 Synopsys:
 BEEP <mode> parameters
 where valid 'parameters' depend on 'mode' as described below:
 - Mode 1 (simple sound)
   BEEP 1 <frequency> <duration>
      to play a single sound.
      Example:
      BEEP 1 440 500
      plays a note of 440 Hz for 500 milliseconds.
 - Mode 2 (iterations of sounds of the same duration)
   BEEP 2 <iterations> <duration> <freq_1> .... [freq_n]
      to play a sequence of sounds of the same 'duration' 'iterations' times.
      Example:
      BEEP 2 5 200 50 100 200 400 800 1600
      plays for five times a sequence of sounds of increasing frequency
      with a duration of 200 milliseconds for each sound.
 - Mode 3 (iterations of sounds of different duration and frequency)
   BEEP 3 <iterations> <freq_1> <dur_1> ... [freq_n] [dur_n]
      to play a sequence of sounds of given 'duration' 'iterations' times.
      Example:
      BEEP 3 5 50 200 1000 400
      plays for five times a sequence of a 50 Hz sound lasting 200
      milliseconds followed by a 1000 Hz sound lasting 400 milliseconds.
 Notes :
   - the frequency must be higher than 36 Hertz and lower than 32 KHz
   - 'duration' is expressed in milliseconds and cannot exceed 10000
   - 'iterations' is limited to 100
