SU711618A1 - Method of magnetic recording and reproducing information represented in binary code - Google Patents

Description

With a return signal and before restoring the binary code, the two-frequency signal is restored by introducing additional pulses into the pulse-reproduced signal sequence, with additional pulses between successive pulses with periods equal to T and 2 T and pulses with a period of 1.5 T between pulses alternately, but by a larger 2/3 and 1/3 of this period, and in the first period equal to 1.5 T, following the period of the house 2T, an additional impulse is introduced by a magnitude of 2/3 of the period. FIG. 1 shows a device that implements the proposed method; in fig. 2 time diagrams of his work. The device works as follows. The reference signal A from generator 1 and digital information B from source 2 are fed to converter 3, where the square carrier B is two-frequency manipulated in accordance with the information signal. Shaper 4. On monopolar carrier fronts, generate a new signal G by dividing frequencies by the floors, which is amplified by amplifier 5 and recorded by head 6 on magnetic media. The signal from the carrier is reproduced by the head 7 and amplified in block 8 (signal P), Block 9 generates a pulse sequence E corresponding to the extreme values of the repetition of the south signal D, This pulse sequence E synchronizes the inertial generator 1O, which monitors the clock frequency oscillations of this sequence caused by instability of the speed of movement of the information carrier. The deviations of the pulses of the signal E from the pulses of the sync signal G represent the temporal distortions of the sc signal of the reproduction signal, which increase with increasing recording density. The block 11 of forming waiting intervals for information on the edges of the clock pulses of the signal W, and in case of their advance with the pulses of the signal E on the leading edges of the leading pulses, produces two pulse sequences 3 and I. These pulses, the pulses of which represent the information waiting intervals The block 11 controls the block 12 of the time distortion corrections. During the intervals within which the pulses of signal E are placed, information is received at block 12 (pulses 3 and 3 of signal 3 and pulses EI to E of signal E, respectively), and the received information is output in the next 1 frame by gating with clock pulses W (pulses Ui and Uj). Consequently, the output of block 12 is the corrected reproduction signal K. Correction of temporal distortions ° Sc is produced within the limits of period 4: repetition of clock pulses or within ± 25% of the period, clock frequency C + 0.25 T). The recirculated K signal of the reproduction signal, coupled to C 1 chromopulse and corrected, arrives at a two-frequency signal recovery unit 13, which uses the repetition of the repetitive pulse sequence in the recovery of a two-frequency signal, which means that between periods with durations of 2 T periods with a duration of 1 , 5T are repeated an even number of times (0,2,4 ...), while the IT period among the 2T and 1.5T periods can alternate anywhere, with any subsequent in any quantity. Itself. the restoration of the two-frequency signal consists in the introduction of an additional pulse in each period of the corrected reproduction signal K. The location of the additional pulse is determined in the two-frequency signal by the distance between the synchronizing pulses, which must be equal to IT. This requirement is met if, during the restoration of a two-frequency signal, for periods with durations of 2T and IT, the additional signal is input in the middle of the period, and for periods with a duration of 1.5 T, the distance of the input pulse from the beginning of the period is taken alternately IT and O, 5T (i.e. 2/3 and 1/3 of this period), moreover, for the first such period, voznashsat r after the period of 2T, this distance is taken IT (i.e. 2/3 of the period). The input additional pulses are generated by a fourfold shift of the pulse sequence Ki by O, 5T (or the period 1 of the sync pulses) using the shift register 15 and the detection of matching pulses in the corresponding shifted pulse sequences of A., M, H and O with noNiomjj decoder 16. From these impulse sequences & relative to sequential sequence AND it can be seen that the hindlines of the 2T periods are consistent with the front pulses of the periods 2T of the sequence O, and their It corresponds to the middle of the period 2T of the pulse sequence M. According to sTHNt, the decoder 16 forms a sequence P of additional pulses introduced during the periods 2T. Similarly, the pulse sequence of the pulses P and VBOD11MYh in the middle periods of the IT sequence M is formed by the pulse and pulse sequences of L and H. For the introduction of additional pulses in periods of 1.5 T, the decoder 16 contains the sequences C and T, when the pulses of the L and O sequences and the E and H sequences, respectively, coincide. The pulses of sequence C are located at a distance IT from the front pulses of periods of 1.5 T, and the dal pulses of the sequence T are 0.5 T. The counting trigger 17, which is reset to the initial position by pulses of sequence P, and switched by pulses of sequence 1, provides the output signal Y to pass through the AND 18 pulses of sequence C for odd periods of 1.5 T (and the Gauls sequence of additional pulses f), and for even periods, the passage of pulses of a pulse sequence T through cIm 19 (pulse sequence X). The OR 2G scheme combines the P, R F, and X sequences of additional pulses and the M sequence into a pulsed AND sequence of the two-frequency signal. Pulse separation (or binary recovery) circuit 14 from the pulsed sequence C separates a sequence of information pulses and a sequence of sync pulses. Using the proposed method makes it possible to increase the reliability of the reproduced information by expanding (twice) the permissible temporal distortions and restoring the two-frequency signal by generating additional pulses from the corrected NMMP with the subsequent signal succession of the signal 11 to Biiona nx in a strictly controlled sequence; M o l a; and the method of magnetic recording and recalling, represented by the binary code, including {two of the two gastric masking of the rectangular carrier at each step of the unit {n and HyasiMH code, halving the frequency of the carrier drops, recording the differences The carrier carries out {1 namapayayuyusta media carrier, reproducing the recorded data and the 1-Fovashgeg & ampoule sequence for the extrection values of the reproduced cggnal, in which and: 2 T, followed by recovery. Enkem from this sequence of a binary code, about t and h.y and y and so that, in order to increase the reliability of the recovered information when the recording density is increased, a synchronization signal is generated, the frequency of which is edited by the average frequency of the 11-pulse sequence the playback signal, correct the temporal distortion of the pulses of this sequence with a synchronous signal and, before restoring: the binary code, restore the two-frequency signal by inputting into the pulse sequence the produced signal of additional pulses, while between pulses of a sequence with periods equal to T and 2T additional 11 pulses are introduced into the middle of the first half of 0, and between and {pulses with periods of 1.5 T - alternately by 2/3 and 1/3 of this period, the first period is equal to 1.5 T, following the perkhed 2T, an additional one and 1 gpuls are introduced for a magnitude of 2/3 periods. Sources of information taken into account in the examination 1. US patent number 3961367, cl. 360- 44, 1976. 2. Makurochkin VG Magnggia recording in computer technology M., Sovetskoye Radio, 1968. 3. USSR author's certificate No. 526OO2, cl. G 11 B 5/02, 1975 (prototom).

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Claims (1)

Claim A method of magnetically recording and reproducing information represented by a binary code, including two-frequency manipulation of a rectangular carrier by units and zeros of a code on each clock cycle, halving the frequency of the carrier drops, recording the carrier drops by changing the direction of carrier magnetization, playing back the recorded signal and generating a pulse sequence. ·! according to the extreme values of the reproduced signal, in which the pulses follow with three durations of periods equal to T, 1.5 T and 2T, with the subsequent restoration of the binary code from this sequence, which is due to the fact that, with In order to increase the reliability of the recovered information while increasing the recording density, a synchronizing signal is formed, the frequency of which is determined by the average frequency of the pulse sequence of the playback signal, and * the temporal distortions of the pulses of this sequence are corrected before the binary code is restored, the two-frequency signal is restored by introducing additional pulses into the pulse sequence of the reproduced signal, while between pulses of the sequence with periods equal to T and 2T, additional pulses are introduced in the middle of the periods, and between pulses with periods of 1.5 T - alternately 2/3 and 1/3 of this period, and in the first period equal to 1.5T, following the 2T period, an additional impulse is introduced by 2/3 of the period.