Format of FaxBIOS GRAPH_OPEN_FILE command buffer:
Offset	Size	Description	)
 00h 12 BYTEs	common data (see #02935)
 0Ch 80 BYTEs	filename
 5Ch	WORD	file type
 5Eh	WORD	graph handle
 60h	WORD	number of pages
 62h  6 BYTEs	future expansion
 68h	WORD	structure size
SeeAlso: #02952,#02954