Abstract: In order to reduce the time losses that arise when reading a plurality of successive data blocks, because of the interruption of the read operation in the case of recognized data errors, all required data blocks are read in one pass and are transferred into a correspondingly enlarged buffer memory (DAT-SP). Error syndromes (ES) resulting from the recognized data errors are initially intermediately stored in allocation to the erroneous data, until a correction of the data in the data memory (DAT-SP) is possible.

Abstract: The storage tracks lying respectively above one another in a disk pack and yielding a cylinder are divided into sectors, whereby a respective plurality of sectors have one respective alternate sector assigned thereto, the latter serving as a useful sector in case a defective sector occurs along the track. The assignment of the defective sectors to the alternate sectors is controlled in such a manner that every occurring defective sector effects a shift of the defective sector and of the following sectors by respectively one sector up to the respectively next, following alternate sector, the shift amplitude after every alternate sector being reduced by one sector length or, respectively, to zero and, in turn, corresponding increased at every following defective sector within the cylinder up to the next alternate sector following thereupon.

Abstract: A method for generating digital actual velocity signals in a positioning system for the write/read heads of a magnetic disk storage utilizes a position signal received from a servo-head to derive digital signals having edges marking the data track centers. Reset signals for a digital counter counted up by clock pulses are formed from the digital position signals and, upon recognition of a zero passage of the position signal, the content of the counter is sampled and the counter is reset. The position signal is then compared with a stored optimum deceleration curve and a coil is operated through a series of gates to appropriately position the write/read heads.

Abstract: A circuit arrangement for recognizing zero transitions of signals includes a zero transition detector which receives the signals and an amplitude evaluator. The zero transition detector produces rectangular pulses which are assigned to the zero transition of the signals and the amplitude evaluator produces amplitude signals which, at least until the occurrence of the next zero transition, indicate that the amplitude of the signals was, prior to this particular zero transition, greater than the amount of a given threshold voltage. A switching stage is provided which is supplied with the rectangular signals and with the amplitude signals and which emits further signals at its output when the rectangular signals and the amplitude signals are present.

Abstract: A rotatable clock disc of soft magnetic material has one or more teeth arranged in an asymmetrical graduation at the periphery for use as a pulse generator with a field plate differential sensing component. Each tooth is in the form of a flap formed by a pair of radially extending cuts spaced apart an interval greater than the width of the sensing component. The flap is bent so as to extend generally parallel to the plane of the disc and provides balance of the disc when rotated.