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 COM(n%) {ON | OFF | STOP}
 
 Usage Notes
   ■ If your program contains event-handling statements and you are compiling
     from the BC command line, use the /W or /V option. If you do not use
     these options and your program contains event traps, Visual Basic
     generates the error message, "ON event without /V or /W on command
     line." See: ◄BC Command-Line Options►
 
   ■ COM(n%) ON enables communications-event trapping at COM port n%. If
     a character arrives at a communications port after a COM(n%) ON
     statement, the routine specified in the ON COM statement is
     executed.
 
   ■ COM(n%) OFF disables communications-event trapping at COM port n%. No
     trapping takes place until another COM(n%) ON statement is executed.
     Events occurring while trapping is off are ignored.
 
   ■ COM(n%) STOP suspends communications-event trapping at COM port n%. No
     trapping takes place until a COM(n%) ON statement is executed. Any ON
     COM events that occur while trapping is suspended are remembered and
     processed when the next COM(n%) ON statement is executed. However,
     remembered events are lost if a COM(n%) OFF statement is executed.
 
   ■ When a signal-event trap occurs (that is, the GOSUB is performed),
     an automatic COM(n%) STOP is executed so that recursive traps cannot
     take place. The RETURN from a trapping routine automatically
     executes a COM(n%) ON statement unless an explicit COM(n%) OFF was
     performed inside the routine.