Format of stream data structure:
Offset	Size	Description	)
 00h	BYTE	1Bh magic value identifying start of stream
 01h	BYTE	stream type (00h, 01h, 10h, 14h-1Fh legal)
		(see #00440,#00446,#00447,#00448)
 02h	WORD	length of remainder of stream in bytes
	var-length fields follow, each an OPCODE followed by
	     zero or more args