Page Comparison

IN:  
      BC = number of byte to write to serial port, maximum 16384, one bank
      DE = input
          DE = 0, input is a file/device opened with its handle in IX 
          DE > 0, input is memory at (DE)
      IX = file handle (if DE = 0)

Out if call succeeded:
      Fc = 0
      BC = remaining time (SI_TMO)
 
Out if call failed:
      Fc = 1
      A = RC_TIME, timeout elapsed
      A = RC_EOF, end of file reached
      A = RC_RP, input device is read protected

      BC = number of bytes not written

Registers changed after return:
      ......../IXIY same
      AFBCDEHL/.... different