A method of forming a cannula from a cannula mandrel assembly comprising a pair of mouthpiecenasal mandrels and a mating facepiece mandrel. Second data bits are stored in the set of memory cells at a second time that is later than the first time by programming the memory cells to assume respective second programming levels that depend on the first programming levels and on the second data bits. The housing is provided with an internal cylindrical surface with an annular recess arranged for accommodating the locking device. Layout data of a semiconductor apparatus are divided into sizes of the basic figures which take reduction in exposure into consideration so as to be classified according to the basic figures. The recess is between the first epitaxial fin and the second epitaxial fin. The control provides a secured communications link between it and the accessory to prevent accessory theft.