Abstract: A system concept and the components integrated therein for storing useful and control information as well as feature items, general components for data flow control of all components integrated in the system concept as well as special components for data flow and process control of interface systems for laser-beam recorders permit handling of useful and control information as well as feature items independently of physical music/data carriers within premastering and the production of glass masters (mastering) in CD plants. All the various types of information are stored in on-line compatible mass storages and automatically transferred into the sectors calling for the information concerned by general data flow control components. Requests for information can be generated manually or automatically.

Abstract: A disk-shaped optical storage medium for binary information, stored seria as a sequence of pits and lands along a spiral track in the form of pits and lands readable by means of a laser beam according to the principle of interference may be identified in a manner preventing confusing and unauthorized duplication in that a selected number of the total lands is formed in the optical reference surface as depressions which are shallow in comparison to the depth of the pits. This identification feature of basically any form may be both so small that it can only be rendered visible by electron microscopic means and so large that it can be detected by the naked eye in diffused light.

Abstract: A method of testing the position of an edit point between an edited magne tape packed in a cassette and a leader spliced ahead of the recording or a trailer spliced after the recording, includes determination of a distance of the edit point from a cue tone situated, for example, at least before the beginning of the recording, or from the end of the recording and generating first and second output signals commensurate with an optical measurement of the edit point and an inductive measurement of the recorded cue tone. In dependence of the position of the recorded cue tone behind the leader or ahead of the trailer as viewed in tape travel direction, a time difference, such as, between the ascending flank of the second output signal and the descending flank of the first output signal, is determined. The determined time difference is then compared with upper and lower limits which define a tolerance range for the position of the edit point before or behind the recorded cue tone.