Format of request block:
Offset	Size	Description	)
 00h	WORD	0004h
 02h	WORD	magic number (FEFEh)
 04h	WORD	buffer for return code (set to 0 before calling)
 06h	WORD	reserved (will be set to client DS)
 08h	WORD	reserved (obviously not used; set to 0 before calling)
 0Ah	DWORD	far pointer to socket handle (2 bytes)
 0Eh	WORD	process handle (see AX=000Fh/SF=0008h)