ppb_rctr
r = ppb_rctr(bus);
ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out));
ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out));
r = ppb_rctr(ppbus);
r = ppb_rctr(ppbus);
*val = ppb_rctr(ppbus);