SU1689986A1 - Digital data recorder - Google Patents

Abstract

The invention relates to instrumentation, in particular to a magnetic recording technique, and can be used in recording and storing information equipment of measuring and computing systems. The purpose of the invention is to increase the recording density by reducing the intersymbol distortion of the reproduced signals. The goal is achieved by introducing the first 8 and second 9 shift registers, the second element OR 11, the element OR NOT 12, the element AND 14 and the output marker bus 15, as well as the corresponding connection of these elements to the coding unit 3 and the input clock and information buses. The recording signal generated by this device is in the form of short rectangular pulses of alternating polarity, in the form of single pulses in the middle of a clock interval for informational O and a pack of three pulses, the first of which is located at 0, 3T or 0.7T, the second - through 0.9T and the third after 1, ST, for informational 1 m, and also from almost three pulses through 0.5T, 1, ST and 1.7T from the beginning of the clock interval for the marker signals (interband spacing) provides an introduction to the predistortion recording signal, which reduces intersymbol distortion It produces a reproducible signal. 1 tab., 3 Il. cl

Description

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The invention relates to instrumentation, in particular to a magnetic recording technique, and can be used in recording and storing information equipment of measuring and computing systems.

The purpose of the invention is to increase the recording density by reducing the intersymbol distortion of the reproduced signals.

Figure 1 shows the structural diagram of the proposed device; Fig. 2 shows timing diagrams of control signals of a coding unit; Fig. 3 shows the recording and reproduction signals.

The device (Fig. 1) contains a series-connected pulse generator 1, a counter 2, a coding unit 3, a shaper 4 bipolar pulses, an output information bus 5. The bits of the bits of the counter 2 are connected to the corresponding address inputs of the coding unit 3, and the outputs of the two highest bits The inputs through the first element OR 6 are connected with the output clock bus 7 and with the clock inputs of the first 8 and second 9 shift registers. The input marker bus 10 is connected to the information input of the first shift register 8 and to the first inputs of the second element OR 11 and the element OR-NOT 12, the second inputs of which are connected respectively to the first output of the first register 8 and to the input information bus 13. The second and third the outputs of the shift register 8 through the element 14 are connected with the first control input of the counter 2 and the fourth information input of the coding unit 3, the first, second and third information inputs of which are connected to the second outputs of the second register 9 shift data input connected to the output of OR-NO element 12, and the second output - to a second control input of the counter 2. The output of the second OR gate 11 is connected to the output bus 15 of the marker.

Using the proposed device, recording is carried out with short pulses of alternating polarity with time intervals of 1T, 1.5T and 2T, respectively, for information signals O, 1 and a marker (interband gap signal), where T is the clock signal of the recording signal.

In the interval 1T, one pulse is formed in the middle of the interval, after 0.5T from its beginning, or after 0.6T from its beginning, after an interval, 1.5Tili before the interval 2T. In the interval of 1.5T, a packet of three pulses is formed, the first of which is at 0, the ST after the IT interval, and 0.4T after the 1.5T interval. Second and third impulses

packs form through 0.9T and 1, ST from the beginning of the interval. In the 2T interval, a packet of three pulses is formed in 0.5T, 1, 3T and 1.7T. Before and after the marker signal

additionally form a single signal O.

The device works as follows.

The counter 2 in the pulse counting mode of the generator 1 generates at the outputs of the bits the signals arriving at the address inputs of the coding unit 3 performed, for example, on a permanent storage device (ROM), as well as clock signals

(FIG. 2B), which are fed through the first element OR 6 to the clock inputs of the first and second shift registers 8 and 9 (made three-bit) and to the output clock bus 7 and from it to the information source

(not shown). The first shift register 8 performs the time delay of the marker signal (FIG. 2M), and the second register 9, the information signal, arriving, respectively, from the input marker 10 and

information 13 tires.

The interband gap signal is generated by a marker signal, during which a signal is generated, which arrives on the output marker bus 15 to the information source and prohibits the output of information at this time.

The coding unit 3 performs the formation of a pulse signal (B) of the recording.

depending on the state of the input signals at its address and information inputs in accordance with the table. The current information signal is signal X2 (A) in FIG. 2, the previous one is X3, and the next is signal XI. The X4 signal is marker. When recording information about O, the counter 2 has a conversion factor of 10, for G a factor is 15, and for a marker signal it is 20. The duration of the marker signal must be at least two clock periods (2T).

For the remaining combinations of address and information signals, they form a zero signal B.

From the output pulse signal B of the coding unit 3, the shaper 4 of the bipolar signals generates a recording signal (Fig. DG). supplied to recording magnetic head for recording on media

magnetic recording (magnetic head and media in figure 1 is not shown).

The clock period T of the frequency of the recording signal is chosen from the condition T / V where 5 is the working gap of the magnetic head and V is the speed of movement of the magnetic recording carrier.

Due to the specified pulse interleaving in the recording signal, the necessary recording distortion and correction of intersymbol distortion of the reproduced distortion of the signals are provided, which reduces these distortions and allows to increase the recording density. In addition, an increase in recording density is achieved by increasing the minimum duration of the intervals between pulses of signals for recording adjacent bits from 0.25T to 0.4T, thereby reducing the duration of the clock signal of the recording signal from T 1.5 d / M to T (5 / V.

Claims (1)

Invention Formula A device for magnetic recording of digital information containing input information and marker buses, serially connected pulse generator, counter, coding unit, bipolar pulse former and output information bus, with the outputs of the corresponding counter bits connected to the address outputs of the counter, the two most significant bits of which, through the OR element, are associated with an output clock bus, characterized in that, in order to increase recording density by reducing intersymbol distortions in generated signals, the first and second shift registers are entered into it, the clock moves connected to the output clock, the OR-NOT element, the AND element and the second OR element, the output connected to the output marker bus, while the input marker bus is connected to the information input first shift register and with the first inputs of the element OR NOT and the second element OR, the second inputs of which are connected respectively to the input data bus and to the first output of the first shift register, the second and third outputs of which through the element AND with They are connected with the first control input of the counter and the fourth information input of the coding block, the first and second and third information inputs of which are connected to the corresponding outputs of the second shift register, whose information input is connected to the output of the OR-NOT element. and the second output is to the second control input of the counter.