Introduction    Serial Communications
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 ComCarrier()    Determines if the Carrier flag is on
 ComHighDTR()    Activates the Data Terminal Ready flag
 ComInEmpt()     Determines if the reception buffer is empty
 ComInFlh()      Initializes the reception buffers
 ComInput()      Extracts a value from the communications buffer (input)
 ComInputS()     Extracts a string from the communications buffer (input str)
 ComInst()       Installs a Serial Communications System
 ComLowDTR()     Deactivates the Data Terminal Ready flag
 ComOutput()     Stuffs a value into the communications buffer (output)
 ComOutputS()    Stuffs a string into the communications buffer (output str)
 ComOutEmpt()    Determines if the transmission buffer is empty
 ComOutFlh()     Initializes the transmission buffers
 ComParity()     Determines the communication parity
 ComReady()      Determines if the system is ready to transmit
 ComSpeed()      Determines the communication speed
 ComUnInst()     Uninstalls the Serial Communications System
 CRC32()         Returns a CRC32 polynomial of a block as PKZIP
 Dial()          Dials a phone number with the modem
 Hangup()        Hangs up the phone