tp_szmodem() - send files using Zmodem

   nError := tp_szmodem(nPort, cFile|acFiles, [cProgress], [nConv])

   nPort       Serial port number.
   cFile       File name.
   acFiles     Array of file names.
   cProgress   Progress function name.
   nConv       File conversion option.

   Returns     Error code.

   Sends one or more files using Zmodem protocol.  You may specify
   either the name of a single file, or an array of file names.  See
   File Transfers for more details.

   nConv, if present, is the Zmodem file conversion option that will be
   applied to each file; see tp_zfconv() for details.

   Example:

       nError := tp_szmodem(1, "C:\UP\TEMP.DBF", "Progress")
       // Examples of progress functions may be found in the files
       // PROGRESS.PRG, RZ.PRG, SZ.PRG, TRANSFER.PRG, TRAN2.PRG,
       // and TRAN3.PRG, in the Telepathy sample code directories.