SU572834A1 - Method of recording/playback of digital information on magnetic carrier - Google Patents

Description

one

The invention relates to the field of instrumentation and can be used when recording and reproducing digital information signals using magnetic recording equipment.

There is a known method of recording digital information signals, in which each binary bit is encoded by two neighboring elements with a number of properties that allow one to have an idea about the reflectivity, magnetization, reversibility and saturation of the working layer of the carrier 1. But due to the fact that the message depends on many signs; this method cannot be used for a wide class of equipment.

There is also known a method of multichannel recording of digital information signals, at which any acceptable base of code 2 can be chosen. But the need to determine the recorded characters not only in the direction of change of the carrier magnetization, but also in its initial level, makes it inefficient to use codes with a small base value .

The closest to the invention in its technical nature is a method of recording - reproducing digital information on magnetic media, based on the use of a binary code and on a single reversal of the carrier for each binary unit, with information recovered at a distance corresponding to the distance between the adjacent sections of the remagnetization 3.

However, this method has limited functionality, which is associated with the asynchronous recording process due to the dependence of the speed of recording information on the number of ones and zeros in the recorded code sequence, and the lack of interference immunity.

In order to expand the functionality and increase noise immunity of the proposed method, when implementing the information recording mode, groups of binary code are converted into groups with a fixed number of code units, and implementing the playback mode of the recorded information, error detection is performed by counting the number of units in the code group.

The implementation of the described method is illustrated in the drawing.

When recording digital information signals, for example, a binary-decimal code, a four-bit code can be converted into a five-bit binary code, in which for each of the ten transmitted code combinations there are three units. It should be the following sequence: binary decimal code transformed code

000111

101011

201101

301110

410011

510101

610110

711001

811010

911100

The drawing shows the entry of the converted code for codes 00111 and 01011, where the unit is represented as an interval between two remagnetization (two sections of the magnetization reversal). The minimum interval is determined by the frequency range of the recording-reproducing path of the magnetic recording apparatus. Zero is determined by an interval twice as long as for a unit.

During reproduction, the distance between adjacent sections of the carrier's magnetization reversal is determined, as a result of which the recorded binary unit is restored. In this case, in each code group, the number of units is determined: there should be, as shown above, exactly three of them. The presence in the code group of a different number of units indicates the occurrence of an error.

four

The proposed method allows for multi-track synchronous recording of information on magnetic media.

Claims (3)

1. The patent of England No. 1290252, cl. G 4M, pub. 1972. 2. US patent number 3357003, cl. 340-174.1, publ. 1967. 3.Patent of France No. 2086576, cl. G IV 11/00, published 1971.