SU1661829A1 - Method for digital data magnetic recording - Google Patents

Abstract

The invention relates to instrument engineering and can be used in magnetic recording equipment of information recording systems and computer technology. The purpose of the invention is to increase the recording density by increasing the information content of the recording signal. According to the proposed method, the recording signal of the eight-bit group — the byte is formed in the form of a tripulse, the polarity of the first pulse is set in accordance with the modulo result of two all byte bits, one of the four values of the first, second, and third impulses of the tripulse is set depending on from the values of certain two bits of a byte, namely the first and second, third and fourth, fifth and sixth bits of a byte. Between the first and second, second and third pulses of a tripulse, an interval (step) is introduced with a single value of the seventh and eighth bits, respectively. The polarities of the pulses in the tripulse alternate. The information content of the record byte signal in the form of a tripulse is 7.5% higher than when writing a byte by dipulses, which makes it possible to increase the recording density accordingly. 2 Il.

Description

The invention relates to instrumentation, in particular to a magnetic recording technique, and can be used in equipment for recording and processing information of measurement systems and computer technology.

The purpose of the invention is to increase the recording density by increasing the information content of the recording signal.

Fig. 1 shows a block diagram of a device for carrying out the proposed method; in fig. 2 - timing diagrams explaining its essence.

The device (Fig. 1), which implements the operations of the proposed method, contains a block 1 of delay and distribution of input information bytes, outputs connected to information inputs of block 2

determine the byte checksum of a group of bytes, the byte checksum 3 of the byte and with the inputs of the first block 4 OR elements, to the other inputs of which as well as to the other inputs of the block 3 the output of the bits 2 of determining the bit checksums is connected. The outputs of blocks 3 and 4 are connected to the inputs of the imager 5 tripulse, the output connected to the input of block 6 of the record

The device also contains a control unit 7, which consists of an generator of 8 sequences of clock pulses of a recording associated with an input to a control bus Record, and a generator of 9 sequences of clock pulses of reproduction associated with an input of an ECM

00

about

Equal Bus Reading. The generator 8 is connected by one output to the control inputs of the delay unit 1 and the distribution of bytes, the blocks 2 and 3 for determining the total and bit checksums and the other output to the control input of the rapper 5 tripuls.

The playback unit 10 is connected to the input bus C of the carrier, the first output is connected to the information input of the former 9, and the second output is connected to the information input of the playback signal decryption unit 11 to which the information inputs of the former 12 bytes are connected; The generator 13 of the signal distortion signal, the generator of 14 total checksums modulo two bytes, the generator of 15 bitwise checksums of groups of bytes. To the combined control inputs of the formers 12-15, connected to the control input of the decryption unit 11, the output of the imager 9 of the repetition clock pulse sequences is connected. The outputs of the drivers 12 and 15 are through the second block 16 of the OR elements, and the outputs of the drivers 9, 13 and 14 are directly connected to the inputs of the block 17 for delaying, rearranging and controlling bytes, the output of this block is connected to the output bus of the device.

The proposed method using the implementing device is carried out as follows.

The signals of the initial binary information sequence (Fig. 2a), coming from the input bus of the device, are delayed and distributed over eight-bit groups - bytes - in block 1 of delay and distribution, and the delay time is 3 N .Max. - maximum duration of group fallouts; N - coefficient corresponding to the number of bytes in the group. FIG. 2 received N 8; t.Vmax.T 2T, where T is the byte recording period (triple-pulse recording period), then the delay value is 1jt 16T (the delay itself is not shown in Fig. 2). Block 1 also performs the allocation and grouping of bytes in the order shown in FIG. 26

In block 2, modulo two homogeneous bits of a group of bytes determine the bit checksums of the first group of bytes (informational 1-1 ... 1-8 and control 1-9), the second group of bytes (informational 11-1 ... 11-8 and control 11-9), etc. In block 3, for each byte, information or check, the checksum modulo

two all its bits (Fig. 2c) and the result obtained correspond to the polarity of the first pulse of the tripulse of the recording signal (Fig. 2d) - for example, positive at zero (first to third and sixth tripulses in Fig. 2d) and negative with a single value of the checksum (the fourth, fifth and seventh tripulses in Fig. 2d). The polarities of the remaining pulses in the tripulse alternate.

The durations of the first, second, and third tripulse pulses are set to one of four values — 1, vi, Gz, or TA, depending on the values of the two corresponding byte bits, namely, the first and second (for the first pulse), third and fourth bits (for second pulse, for the third pulse (for the third pulse), while the minimum duration of the pulse is set for two digits to the duration of Г2 ri + Л g - for values of тз п + 2Дг- with 10 for duration and Г4 Г1 + ЗАг for values 11.Time intervals (steps) with a duration of Dg 0.2 p between the first and second and between the second and third pulses of the tripulse are set at unit values of the seventh and eighth bits of the byte, respectively (the first, fifth, sixth and seventh tripulses in Fig. 2d).

The tripulses formed in the imaging unit 5 according to the indicated rules are fed to the input of the recording unit 6 for recording on the carrier.

The recording signal of the proposed method — tripulse — carries nine bits of information, namely, eight information (bytes) and one control. The maximum duration of a tripulse with a maximum duration of 1.6 tons of each of its three pulses and the presence between them of steps Ј 0.2 tons (the first tripulse in Fig. 2d) is measured, relative to the duration of the minimum interval t and the minimum distance between the pulse and the beginning and the end of the recording interval T (recording interval of a tripulse), taken equal to 0.5.,

Ttrip.max 0.5 G1 +3 G4 + 2 Dg + 0.5 G1

ri +3 "1.6p + 2-0.2 ri 6.2 p.

The information content of the recording signal when recording in the form of a tripulse is (relative to n) P 1.45 bit / p, which

and frl

7.5% higher than when recorded by dipulses in the prototype method, informative

which under the same conditions is 1,356m7rv

The pulse sequence reproduced from the magnetic recording medium is amplified in the playback unit 10 (FIG. 5 2d) and is fed to the shaper 9 of the playback clock sequences and to the playback signal decryption unit 11. (In Fig. 2d, the hatching marks the signals dropped by group 10 conditionally). In block 11, decoding using the shaper 12 generates byte signals (Fig. 2e), using shaper 13 produces signals of signs of distortions of tripuls, at which they are not decrypted 15, but restored by further processing, in the shaper 14 they form checksum byte signals (Fig 2g), with the help of the imaging unit 15, signals of random control-20 sums of groups of bytes are formed (Fig. 2e).

The sequences of signals from the outputs of the formers 12–15 (the dropped out signals in Figures 2e and 2c 25 are marked with dashes) formed after decoding the playback signals go to block 17, where they are delayed for a time.

u1out.max. 16 T 1.6 Htrip .. Ie Ne same

time, as during recording, controls the correctness of decoding bytes or distorted or triple pulses and in case of distortion, restore the values of the fallen signals by incrementally modulo two bits of seven undistorted bytes of the group consisting of distorted bytes, 35 and bits of bitwise control the sums of the same group, interpreted from the “control tripulse circuits” (in fig 2z, the recovered bytes are circled). Then, 40 bytes are rearranged in the appropriate order of their following in the group, and after excluding the control (additional) bytes, the output of the device receives signals from the output binary informative sequence 45 (Fig. 2i).

Claims (1)

Thus, the proposed method allows, by increasing the information content of the recording signal when it is formed in the form of a tripulse, to increase the information recording density on the magnetic recording media, while retaining the ability to detect and correct group failures. Claims The method of magnetic recording of digital information, in which the signals of the input binary information sequence are distributed over eight-bit groups - bytes, modulo two values of bits of each byte and bitwise modulo two modules of the same name of a given number of bytes spaced apart from each other for an interval longer than the maximum duration of group failures, and form a recording signal of information and control bytes in the form of a group of pulses, polarity and g the length of which, as well as the existence of intervals between pulses, is set in accordance with the results of the total and bitwise modulo two summation and the values of one or several specific bits of each byte, characterized in that, in order to increase the recording density by increasing the information content of the recording signal , the byte recording signal is formed in the form of a tripulse with alternating polarity of pulses, in which the polarity of the first pulse is set in accordance with the result of modulo two in Ex bits of a given byte form one of the four values of the first, second and third pulses depending on the values of the corresponding two byte bits, namely the first and second, third and fourth, fifth and sixth, and also form the intervals between the first and the second the second and between the second and third pulses of a tripulse with unit values of the seventh and eighth bits of the byte, respectively. To carrier t Reading g- ± With carrier one fe, /