SU1282206A1 - Device for reproducing digital information - Google Patents

Abstract

The invention relates to magnetic recording and allows to increase the accuracy of information reproduction, for this information is entered into the buffer memory 2, the readout of which is produced by a stable frequency from the crystal oscillator 7 through frequency divider 9. Loss of information is eliminated by controlling the speed of movement of the magnetic media depending on the memory capacity. Dp reducing the effect of outliers causing clock failures and the violation of the sequence of addresses in the buffer memory 2, the speed is controlled through a reversible counter 4, working from a quartz oscillator 7, whose frequency is constant and does not depend on the playback signals. The division ratio of the controlled frequency divider 6, with and without precipitations, will alternate by one, which guarantees the synchronous operation of the master drive of the magnetic storage device 1, 1, or 10. (L

Description

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The invention relates to magnetic recording, in particular to digital information display devices.

The purpose of the invention is to increase the fidelity of reproduction by reducing the dynamic error,

The drawing shows the structural scheme of the device.

The device contains a magnetic memory device 1 connected in a certain way, a buffer memory device 2, an address comparison unit 3, a reversible counter 4, a decoder 5, a controlled frequency divider 6, a first 7 second 8 quartz oscillators, a first 95 B 1 E 10, a third 1 1 and a fourth I 2 frequency dividers , comparator 13 output information bus 14 .. synchronizing shitsu 1 5.

The device works as follows.

The signal reproduced from the magnetic carrier is stored in the buffer memory 2. The information is read from the buffer memory 2 at a stable frequency from the crystal oscillator 7 through a frequency divider 9. The address spacing unit 3 analyzes the time relation between the corresponding write addresses and the readings in the buffer storage device and, depending on their ratio, issues the More, Less or Equal commands. These commands switch reversing counter 4 to Count mode Forward, Back, and Stop. The counting input of the reversible counter 4 is supplied with a signal from the crystal oscillator 8

. The system tends to occupy such a position where the readout addresses are shifted relative to the write addresses by 1/2 the volume of the buffer unit. In this case, from block 3 of the comparison of addresses, the stop command is sent to the reversible counter 4. Any deviation from this state leads to a change in the speed of movement of the magnetic carrier in the magnetic storage device 1J, a change in the frequency of information arriving in the buffer storage device and, therefore, the restoration of the ratio between the write and read addresses.

If there are precipitations on a magnetic medium, causing clock frequency failures and violation of the sequence of addresses in the buffer storage device, dynamic distortions do not occur, since the reversible counter 4 operates from a quartz oscillator 8, whose frequency is constant and independent of reproduction signals. At the same time, the division ratio of the controlled frequency divider, with and without outliers, alternately changes by one, which guarantees the synchronous operation of the master drive of the magnetic storage device.

Thus, the device provides reproduction of digital information from a magnetic carrier without increasing the error during a drop-down of a scientific research institute.

(rmula of invention

through a frequency divider 12, the division factor of which depends on the iner- tion of the master drive of magnetic digital information, containing the storage device 1, the output ferronic memory device, the return signal of the reversible counter 4, the decrypt- 45 keyed information inputs terminate decoder 5 and controls the information outputs of the magnetic

the division factor of the active divider is 6 frequencies. The signal from the output of the controlled divider 6 part through the frequency divider 10 is fed to the first input of the comparator 13, to the second input of which through the divider 11 comes a signal from the speed sensor of the magnetic driver in the magnetic storage device 1, the Comparator 13 compares the frequencies of the incoming signals and produces the speed control signal of the magnetic carrier in the magnetic storage device

storage device, output to the E output bus, synchronization input to the synchronization bus and to the output of the first frequency divider and address outputs to the inputs of the address comparison unit, the first crystal oscillator connected by the output to the input of the first frequency divider, serially connected controlled divider frequency, the second frequency divider and a comparator, the output of which is connected to the control input of the magnetic storage device.

the third divider lacTofbi connected between the output of the speed sensor of the magnetic carrier in the magnetic storage device and the second input of the comparator, the second crystal oscillator connected to the input of the controlled frequency divider and the control bus connected to the control inputs of the first, second and third frequency dividers and control output of the magnetic memory device, so that, in order to

by reducing the dynamic error, a reversible counter, a decoder and a fourth frequency divider are introduced, the input of which is connected to the output of the second crystal oscillator, and the output is connected to the counting input of the reversible counter, the control inputs of the reversible counter are connected to the corresponding outputs of the block comparison of addresses, and its outputs through a decoder are connected to the inputs of a controlled frequency divider.

Claims (1)

Claim A device for reproducing digital information, comprising a buffer memory connected by information inputs to the information outputs of a magnetic memory device, an output to an output bus, a synchronizing input to a synchronizing bus and an output of a first frequency divider, and address outputs to inputs of an address comparison unit, the first a crystal oscillator connected by an output to the input of the first frequency divider on the device 1. The comparator 13 compares the frequencies of the incoming signals and generates controlled the speed of movement of the magnetic medium in the magnetic storage device 55 series-connected controlled frequency divider, a second frequency divider and a comparator, the output of which is connected to the control input of the magnetic storage device, a third frequency divider connected between the output of the magnetic carrier speed sensor in the magnetic storage 'and the second input of the comparator, the second quartz oscillator 5 connected to the input of the controlled frequency divider, and a control bus connected to the control inputs of the first, second and third frequency dividers and the control output of the magnetic storage device, characterized in that, in order to increase fidelity of reproduction by reducing dynamic error, a reversible counter, a decoder and a fourth frequency divider are introduced into it, the input of which connected to the output of the second crystal oscillator, and the output is connected to the counting input of the reversible counter, the control inputs of the reversing counter are connected to the corresponding outputs of the address comparison unit s, and its outputs through a decoder are connected to the inputs of a controlled frequency divider.