COM_GETIO()
 Determines the base address of a port
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 Syntax

     COM_GETIO(<nComPort>) --> nIOPort

 Argument

     <nComPort>  Designates the port (1 to 4) to which the current I/O
     address is delivered.

 Returns

     COM_GETIO() returns the I/O address of the designated port.  With an
     invalid parameter or an unavailable port, the function returns a value
     of -1.

 Description

     COM_GETIO() determines with which port I/O address CA-Clipper Tools
     functions communicate.  This function only returns a value known to
     CA-Clipper Tools software.  It cannot determine the I/O address of an
     interface card!

 Examples

     .  Determine the COM1 I/O address:

        ? COM_GETIO(1)               // 1016

     .  Specify that you need the address in hexadecimal form:

        ? NTOC(COM_GETIO(1), 16)     // "3F8"

     .  Specify an invalid port number:

        ? COM_GETIO(5)               // -1