385 struct	msgb {  struct
386 	struct	msgb	*b_next;  argument
387 	struct  msgb	*b_prev;  argument
388 	struct	msgb	*b_cont;  argument
389 	unsigned char	*b_rptr;
390 	unsigned char	*b_wptr;
391 	struct datab	*b_datap;
392 	unsigned char	b_band;
393 	unsigned char	b_tag;
394 	unsigned short	b_flag;
395 	queue_t		*b_queue;	/* for sync queues */