Format of IPX Event Control Block:
Offset	Size	Description	)
 00h	DWORD	Link
 04h	DWORD	-> Event Service Routine (00000000h if none) (see #03814)
 08h	BYTE	in use flag (see #03812)
 09h	BYTE	completion code (see #03813)
 0Ah	WORD	(big-endian) socket number (see #03809)
 0Ch  4 BYTEs	IPX workspace
 10h 12 BYTEs	driver workspace
 1Ch  6 BYTEs	immediate local node address
 22h	WORD	fragment count
 24h	var	fragment descriptors
		Offset	Size	Description
		 00h	DWORD	-> fragment data
		 04h	WORD	size of fragment in bytes.
Notes:	ESR is a far procedure that is called when the ECB has been handled.
	  On call, the in use flag is zero if the ECB has been handled,
	  non-zero otherwise. If the flag is zero, the completion code holds
	  the result of the event.
	the first fragment should start with an IPX header (see #03815)
	all fragments are concatenated and sent in one piece
	node address FFh FFh FFh FFh FFh FFh broadcasts to all nodes
SeeAlso: #03811