SU1216793A1 - Method of recording and reproducing digital information - Google Patents

Abstract

The invention relates to magnetic recording, to methods for recording and reproducing digital information, and allows for increasing the recording density and improving the self-synchronization conditions. To do this, before recording, the difference between the sum of single bits and the sum of zero bits is determined. Based on the result of determining this difference, the value of the marker signal is formed, and the information byte signal is recorded in a forward or inverse code depending on the result of determining the difference of sums of single and zero bits. in a byte, and the information byte signal is reproduced in a forward or inverse code depending on the value of the reproduced marker signal. In general, the minimum density is 1, 38, when the number of zeros in a binary word is equal to the number of ones. In the first bit, one is written and the word is represented in the direct code. The maximum density is achieved in the case of writing solid ones in a binary word and is 2. The average recording density is 1.69. 1 il. W go a j so oo

Description

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The invention relates to magnetic recording, in particular to methods for recording and reproducing digital information.

. The purpose of the invention is to increase the recording density and improve Uelo-B1-W self-synchronization.

The drawing shows timing diagrams.

The method of recording and reproducing digital information is produced by sequentially recording signals of informative scions bytes consisting of a sequence of bits and separated by a time interval jj, with the magnetic carrier being re-magnetized by the signal of each bit, with an interval of me; For the unit bits, 20 times less than the zero bits, the sum of the unit bits in a byte is determined before recording, and the marker signal is recorded in the time interval. ction 25 result magnetic recording.

In addition, before recording, the difference between the sum of single bits and the sum of zero bits is determined, according to the result of determining this difference, the value of the marker signal j is formed, and the signal J :( the information byte is written in the forward or inverse code depending on the result of determining the difference of the sums of values single and zero bits in the database, and the signal of the information byte is reproduced in forward or inverse codes depending on the value of the reproduced marker signal.

When recording digital information signals, for example, a binary word 10111101 (1 a), one is recorded in the first bit, since the number of ones in a binary word is greater than the number of zeros and the binary word is represented in the forward code.

When the playback mode is implemented, the first bit is downloaded, which in this case corresponds to one over the minimum interval. Then the binary word itself is read in the forward code, since one is read in the first bit.

When writing a binary word with a predominance of zeros, for example, 10100001 contains a zero in the first bit and the binary word is represented in an inverse code. When implementing the mode

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The first two-bit playback reads a zero in the interval between two adjacent -E magnetizations E two times larger than for the unit, and the binary word itself is read in the inverse code.

In the first case, when recording the playback of the binary word 10111001, the recording density is 1.64 tons, e. In one period of the clock frequency, 1.64 bits of information are transmitted; including the extra first bit, in the second case, for the binary word 10100001, the recording density is 1.38, i.e. in one period of the disease; the frequency is transmitted to it; 1.38 bits of information, including the optional .per .bits,

In the general case, the minimum density is 1.38, when the number of zeros in a binary word is equal to the number of ones. In this case, in the first bit, the unit is written down and the word is represented in the direct code. Maximum density is achieved when recording C. FLAT units in a binary word and is 2. Thus, the average recording density is 1.69.

The recording of signals, bytes of information also allows an increase in the power of the clock frequency in the reproduced signal, which improves the conditions for self-synchronization of reproduction.

The use of the invention allows to increase the recording density and improve the self-synchronization of the reproduction of digital information.

Claims (1)

Invention Formula The method of recording and reproducing digital information by sequentially recording information byte signals consisting of a sequence of bits and separated by a time interval, the magnetic carrier re-magnetizing is carried out by the signal of each bit with the interval between the neighboring magnetization reversal for the single bits twice as small as the zero bits before recording, the sum of one-bit bits is determined in a byte and a marker signal is recorded in a time interval, after which the result is reproduced magnetic recording, about tl and h a-yu rd and and so that, with the aim of 31 Consider the recording density and improve the self-synchronization conditions. Before recording, the difference between the sum of the unit bits and the sum of the zero bits in the byte is determined. Based on the result of determining this difference, the value of the marker signal is formed, and the information byte signal is written Period / nff / (/ nupoSof / i / First Sum WELL IT Compiled by V.Dobrovolsky Editor O.Golovach Tehred O.Netse Proofreader G. Reshetnik Order 1002/59 Circulation 544 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Branch ShSh Patent, Uzhgorod, st. Project, 4 216793 in the forward or inverse code, depending on the result of determining the solubility of the sums of the values of the single and zero bits in a byte, and the information bypassing the information is reproduced in the forward or inverse code, depending on the value of the reproduced marker signal.