Abstract: A real time analyzer is disclosed and is adapted to determine the frequency response of a frequency dependent system based on a statistical average of the real time input and output signals of the frequency dependent system, distinguishing between "valid" and "invalid" data as those terms are predefined, so that the response can be measured with any arbitrary input signal to the frequency dependent system.

Abstract: An information storage and retrieval system including an information containing cartridge, specifically a tape cartridge, and an apparatus for retrieving information therefrom is disclosed herein. The cartridge contains its information on magnetic tape within the housing and the latter has an opening for gaining access to the magnetic tape by the retrieval apparatus. At the same time, the cartridge housing carries a cover movable between a first position for covering the opening in order to protect its interior, especially the magnetic tape, from dust and other elements in the ambient surroundings and a second position for uncovering the opening in order to gain access to the tape.