Int 61 Fn 1C  - Pc/tcp Kernel V2.05+ - "net_writeto" - Write A Datagram    [N]

   AH = 1Ch
   BX = network descriptor
   CX = number of bytes to transmit (0000h allowed)
   DX = send options (see #3135)
   DS:SI -> data to be written
   ES:DI -> "addr" structure (see #3133)

Return: CF clear if successful
       AX = number of bytes actually written
       DX = ???
   CF set on error
       AX = error code (see #2990 at INT 61"FTP Software")

Note:  this function differs from AH=1Ah in that the address and socket
     numbers can be overridden

See Also: INT 61"FTP Software",INT 61/AH=00h"PC/TCP",INT 61/AH=1Ah,INT 61/AH=1Dh

See Also: INT 63/AH=21h"BW-TCP"