SU1177848A1 - Method of magnetic recording of digital information signals - Google Patents

Abstract

METHOD OF MAGNETIC RECORDING OF SIGNALS OF DIGITAL INFORMATION, in which the input binary sequence of signals with a bit-interval duration - L "yes g / s ..," /%.,., -., -. ,one,.,. , - -.f-ffe ,. la T is transformed by group transcoding into a ternary sequence of O. 1 and 2 signals, after which a recording signal is generated Without returning to zero with a single current switching when recording a signal of every 1, with a double current switching and predistortions when recording a signal of each 2, differing in that, in order to increase the fidelity of the playback result, the bit interval duration of the transformed ternary signal sequence is set to 4/5 T, and the duration of the smallest and largest time integers the eaves in the recording signal between adjacent signals 1 € or 2 is set equal respectively (L mi 8 / 5Т and 41.

Description

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G6 J1 The invention relates to instrument making, namely to magnetic information recording, and can be used in digital information recording equipment on magnetic recording media. The purpose of the invention is to increase the fidelity of the result, reproduction. FIG. 1 shows a block diagram of a device that implements the operation of the proposed method; in fig. 2 - timing charts of signals, explaining the operation of the device. The device (Fig. 1), which implements the proposed method, in the recording channel contains input information bus 1 and input signal URI with 2 signals Recording resolution, as well as series-connected synchronic unit 3, information converter 4, equalizer 5 of recording signals, counting trigger 6, amplifier 7 recordings, magnetic head 8, the latest recording on magnetic recording medium 9. In the playback channel, the device comprises a serially connected amplifier 10 of the playback signals, a shaper AND of the playback signals, a synchronization and detection unit 12, a gating and decryption unit 13, the output of which is the output information bus 14. The synchronization and detection unit 12 is also connected to the sync pulse generator 15 reproduction, the first output of which is connected to the gating and decryption unit 13, and its second output is the output bus of 16 clock pulses. The reproduction signal amplifier 10 is also connected to the magnetic head 8 and the signal input bus 17. The reproduction resolution. The essence of the proposed method of magnetic recording of digital information signals is explained in the description of operation of the device. Input information in the form of a binary sequence of signals. the duration of the bit-interval T (FIG. 2 a), from bus 1 and sig. The recording resolution from the bus 2 enters the synchronization unit 3, in which the synchronization information input is formed with a period of 21 (FIG. 2d) The input information signals and the synchronization signals with a period of 2 T are then sent to the information generator 4, in which the group coding is implemented signals of input binary information into a ternary sequence of signals O, 1 and 2 and its synchronization, while the bit interval in the ternary sequence of signals is set to 4 / 5T, 8 and the period of the sync signal for it is 8/5 T (Fig. 2e), .. For this, each group of signals corresponding to the four bits (bits) of the input binary information is first converted in accordance with the basic conversion algorithm (Table 1) into pibit (pythyroid) group is transformed. binary information in which between two. bits 1 must be at least one and no more than four zero bits (Fig. 20). If the docking of two adjacent five-bit groups of converted binary information violates the maximum (no more than four) number of zero bits, then additional conversion of signals is performed in accordance with the additional conversion algorithm (Table 2), for which seven bits of the converted binary are analyzed. information (five bits of the current group and two bits from the previous or next group). After the main and additional conversions, the following two signals (bits) 1 in the converted binary sequence of signals correspond to signal 2 and receive a ternary sequence of signals O 1 and 2 (Fig. 2 I), which in the form of pulses (Fig. 2 5K) is fed to the equalizer 5 recording signals. In this corrector, the distortions are performed, namely, the second pulse of the signal 2 is shifted towards the front and, thus, the moment of formation of the second switching of the recording current (the predistortion is shown by dashed lines in Figs. 2 and 5) so that during playback the peak of the signal corresponding to this second switching current when recording signal 2, exactly corresponded to the boundary of its bit interval. From the output of the corrector 5, signals are sent to the counting input of the trigger 4, from the output of which the paraphase signals are sent to the recording amplifier 7, then to the magnetic head 8 and recorded on the magnetic recording carrier 9. I The write current (Fig. 2) is formed by the method without returning to zero, while the signals of each 1 are recorded by a single switching of the current at the end of the bit intervals corresponding to these signals, and the signals of each 2 are recorded by double switching of the current at the beginning and end of corresponding to these signals, bit intervals. The longest (t min) and longest (T max) time intervals in the recording signal between adjacent signals 1 and 2 are 8/5 T and 4 T, respectively. When playing back the information recorded by the proposed method, each signal 1 corresponds to one half-wave of the reproduced signal, and to each signal half-wave, or doublet (FIG. 2 o). Reproduction is carried out by known operations in the playback channel of the device (Fig. 1). The combination of these operations includes amplification in the amplifier 10 of the playback signals from the magnetic head 8 in the presence of a signal at the input of the amplifier 10 Resolution of playback from the bus 17, peak detection and formation of pulses on the peaks of each half-wave of the reproduced signals 1 and 2 (doublets) performed by the driver 11 playback signals. Then, in block 12 of synchronization and detection, the doublet signals are detected, based on the fact that the pulses that form the doublet, even taking into account the time shift of these signals, due to the inter-discharge effect when recording with high density, are closer from each other. than pulses from signals in all other cases (, Fig. 2k), moreover, in this block 12 the synchronization signals are generated by combining pulses 1 and second pulses forming a doublet (Fig. 2 A), the time intervals between which are us 4/5. The pulses corresponding to 1 and second pulses of signals 2 (Fig. 2 m and m, respectively) are received in block 13 of gating and decryption, where the inverse transformation and restoration of the initial information (Fig. 2n, p, c) is carried out according to algorithms inverse to the algorithms of the main and additional signal transformations during recording (Tables 1 and 2), after which the output information is fed to bus 14. Sync signals (Fig. 2 (v) are fed to the synchro generator 15 and are used to synchronize the controlled sync generator with a period of 8/5 T (Fig. 2o), with the help of which gating and decryption of information in block 13 is performed, in addition, output clock pulses with a 2 T period (Fig. 2T) are output from this clock to the output clock 16 clock pulses. Table 1

Note. The symbol X denotes the rank of the preceding or following groups of transformed information, the value of which is indifferent for additional conversion of the current group of transformed information ..

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table 2

Claims (1)

METHOD FOR MAGNETIC RECORDING · 'DIGITAL INFORMATION SIGNALS, in which the input binary sequence of signals with a duration of the bit interval T is converted by group recoding into a ternary sequence of signals “0”. “1” and “2”, after which they form a recording signal “Without returning to zero” with a single switching of current when recording a signal of each “1”, with double switching of current and pre-emphasis when recording a signal of each “2”, characterized in that , in order to increase the fidelity of the playback result, the length of the bit interval of the converted ternary sequence of signals is set equal to 4/5 T, and the duration of the smallest and largest time intervals in the recording signal between adjacent signals “1” or “2” is set to respectively equal to 8/5 T, and T 4.