SU1046763A1 - Method of recording and reproducing digital information - Google Patents

Abstract

A METHOD FOR RECORDING AND PLAYING DIGITAL INFORMATION, namely, that information is recorded with signals of a sequential code and words are formed at the beginning of each word, and the playback of each recorded word begins with highlighting the signal of the marker, characterized in that the recording density, the K1-bit characters of the current and preceding sequences are compared, and the current i-word of the current word is produced by the signal t-times the same code with equality (Kt) of the last the bits in these words, where p. K, and when reproducing the signals of each current word of the sequence, determine the number of bits of the signal of the current code and, after extracting the signal of the next word marker, to the reproduced signal t, -signal of the code, add a group of (L (K-t-) last bits of the signal of the preceding word of the sequence.

Description

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ABOUT)

00 The invention relates to a magnetic recording technique and can be used when recording to reproduce information on magnetic media. Methods are known for recording and reproducing digital information with a pulse width modulation (PWM), which consists in the fact that the information represented by a sequence of K-bit words is recorded by a sequence code of pulse widths, and at the beginning of each word a separator (marker), while reproducing each recorded word begins with the selection of the divider (marker) lj. The closest to the proposed is a method of recording and reproducing digital information, which means that The memory is recorded sequentially by a pulse width pulse code, and at the beginning of each character a separator is set, each recorded character is played, the separator is selected, then the duration of different polarity signal regions for each received bit is calculated, then the ratio of the durations of alternating polarities is calculated signal for each received bit of information and a separator, the separator is separated by the value of the received ratio, and the value of the received bit is determined and 2D Information The use of the above methods for recording and reproducing information represented by a sequence of K-bit words is ineffective due to the fact that the redundancy between the adjacent words of the sequence is not taken into account, leading to a decrease in the density of information recorded. Indeed, most of the adjacent words of a sequence contain the same groups of bits, which are needed to be written only in the current, but not in the subsequent word of the transmitted sequence. The purpose of the invention is to increase the recording capacity. This slot is achieved by the fact that according to the method of recording and reproducing digital information, which consists in the fact that information is recorded by signals of a sequential code in the form of words, and at the beginning of each word, a marker signal is formed. at the same time, each recorded word starts with the selection of the marker signal, the K-discharge signals are compared: the current and preceding words of the sequence and the current i-word is compared with the n-bit code when the last bits are equal () The words in each word of the sequence determine the number of bits of the current code signal and, after extracting the signal of the next word marker to the reproduced signal m - bit, yes added group from (K-m) bits of the last word of the preceding signal sequence. FIG. 1 shows a device that implements the proposed method; Figures 2-5 are diagrams explaining the essence of the proposed method. A device that implements the proposed method of recording and reproducing digital information contains input drive 1, information inputs connected to an external device, and information outputs to the corresponding inputs of register 2 of the current i-ro word, the bit outputs of which are connected to the first inputs of block 3 of bit comparison, modulator 4, one. of the inputs of which is connected to the serial output of register 2 of the current i-ro word, which is also connected to its sequential write input and to the input of register 5 of the previous (1-1) -th word, the bit outputs of which are connected to the second inputs of block 3 of the same comparison, the output of the modulator is connected via output block 6 to the head 7, and the clock and control inputs of the modulator are connected to the corresponding outputs of the control unit 8, the inputs of which are connected respectively to the output of the unit 3 of the one comparison and to the output of the counter 9 of the number K, the setting and counting inputs of which are connected to other corresponding outputs of the control unit 8, one of the outputs of the block 8 united with another input of the input drive 1, and the other connected to the inputs of the parallel recording of registers 2 and 5, the last of its output is connected to the setup input of the register 5 of the previous (i-l) -ro word.

In the receiving part, the device contains a read head 10 connected via input 1 block 11 to demodulator 12, one of the outputs of which is connected to control inputs of multiplexers 13 and 1, and its other outputs are connected respectively to one of the inputs of register 15 (1 1) -th word and with other inputs of multiplexers 13 and the third input of the latter is connected to the output of the generator 16 pulses, and its output is connected to the synchronization inputs of the counter

17 numbers К and register 15 of the previous (-1) -th word, parallel outputs of which are connected to the inputs of the block

18 registration, and the serial output of the register 15 is connected to the corresponding blocks 18 of the registration and multiplexer 13 whose output is connected to the input of the serial record of the register 15 of the previous (1-1) -th word, the output of the counter 17 of the number K is connected to another input of the demodulator 12

and block 18 registration, the output of which is connected to an external device (receiver).

The proposed method is implemented as follows ..

Information entering the input accumulator 1 in the form of a word, having, for example, K-8 bits, is recorded at the beginning of a recording cycle by a signal from control unit 8 with a parallel code in the register 2 of the current I-th word. In register 5. of the previous (I-.1) -th word, the previous transmitted word is written. Register 5 is set to its initial state upon the start of writing a data block.

The control unit 8 sets the counter 9 of the number K to its initial state and generates a control signal arriving at the modulator input. By this signal and using the modulator, a word separator signal (marker) is generated, which is recorded through the output block 6 and the recording head 7 on a magnetic carrier (Fig. 2-). one

At the same time, information from the outputs of registers 2 and 5 is fed to the corresponding inputs of block 3 of bitwise comparison, with which the bitwise comparison of the previous (1-1) -th and current i-ro spruce is carried out.

In the future, for each corresponding: to the interim signal of the control unit 8

the increment of the number recorded in the counter 9 of the number K occurs by one and the information stored in registers 2 and 5 is shifted, so that each bit of information received from the serial output of register 2 of the current 1st word is fed to its input is a sequential write, the input is a sequential write of register 5 of the previous (il) -ro word and the corresponding input of the modulator k. Information signals and clock pulses from the control unit 8 control the operation of the modulator, with which through the output unit 6 and the recording head 7 record information on magnetic media. This process is repeated until alignment of the contents of registers 5 and 5 occurs ( Fig. 3) or the counter 9 of the number K will not overflow. After aligning the numbers recorded in registers 2 and 5, the signal from the output of block 3 of bitwise comparison, control block 8 at an accelerated rate of output should increment the contents counter 9, the number K and the shift of information in registers 2 and 5. At the same time, the operation of the modulator is prohibited by the corresponding signal from control block 8, therefore, those bits of information recorded in register 2 of the current i-ro are equal to the corresponding bits of information recorded in The word 5 register of the previous (1-1) -th, and the magnetic medium is not recorded.

After the overflow of the counter 9 of the number K (FIG.), The cycle of recording the word of information on magnetic media ends, the register 5 of the previous (1-1) -th word stores the recorded word, and the control unit 8 starts the next recording cycle.

When playing information from a magnetic medium (Fig. 5a) through the read head 10 and the input unit 11 enters the demodulator 12, which, prior to reading the information block, sets the register 15 (1-1) -th word to the initial state (Fig. 56) at time t.

At the time tv, the previously received information word is stored in register 15 of the previous (1-1) -th word (Fig. 5i). The demodulator 12 generates information signals (FIG. 5d). accompanying them with the tacts of receiving each bit of information (Fig. 5e). The information signals through the multiplexer 13 are sequentially written down into the register 15 (1-1) of the th word (Fig. 5i) by the clock signals (Fig. 5) The number of clocks received through the multiplexer T is counted with the help of a counter 17 of the number K. With the help of a demodule A word separator (marker) is extracted from torus 12. From the time point tj, when the marker is already selected (Fig. 5c), the input is registered; 15 N (il) -ro words go through the multiplexer 13 to its input, and the register 15 is clocked, (il) -ro words with signals from the 16-pulse Generator via multiplex p T (FIG. 5g). The K number counter 17 counts the number of clock pulses. After the number of information bits shifted. 3 6 words stored in register 15 (il) -ro from the moment information is started will be equal to the number of bits The register register 15, in the counter 17 of the number K, overflows, and it generates a pulse (Fig. 5h), which records the received information to the registration unit 18 and prohibits the flow of information from the demodulator 12 (Fig. 5c). Using the proposed method of recording and reproducing digital information allows for an increase in the recording density in comparison with the known ones. For example, for texts written in KOI7 (GOST 13052-7) and KOI8 (GOST 1968-7) codes, the recording density increases at least 1, 75 and 1.6-2 times, respectively. Information compression is also achieved in the use of inter-sign correlations, and the recording of repeated signs.

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Claims (1)

METHOD FOR RECORDING AND PLAYING DIGITAL INFORMATION, which consists in the fact that the information is recorded by serial code signals in the form of words, and at the beginning of each word a marker signal is generated, while the playback of each recorded word begins with the selection of a marker signal, characterized in that, for the purpose of increase the recording density, compare the signals “-bit of the current and previous words of the sequence and record the current i-ro words produce a signal mj-bit code with equality (K-PC) of the last bit number of bits in these words, where m ^ K, and when reproducing the signals of each current word of the sequence, the number of bits of the signal of the current code is determined, and after the marker signal of the next word is allocated to the reproduced signal of the m ^ -bit code, add a group of (K-m bits of the signal 'preceding word sequence.