SU1679540A1 - Device for magnetic recording digital information - 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 increasing the information capacity of the implemented method and by changing the intervals of the recording pulses, which allows reducing the distortion of the reproduced signals. The goal is achieved by the addition of four elements HE 7-9, 13, three elements AND 10-12 and a shift register 6, to the input of which information information input 15 of the device is connected, and the remaining elements connected between the register and information inputs of the multiplexer. 1 tabl. 2 Il.

Description

The invention relates to instrumentation, in particular to a magnetic recording technique, and may. . Used in the equipment for recording and accumulating measurement and computing systems.

The purpose of the invention is to increase the recording density by increasing the information capacity of the implemented method and by changing the intervals of the recording pulses, which allows reducing the distortion of the reproduced signals.

The recording is carried out with short rectangular pulses of alternating polarity with time intervals of 1 T and 1.5 T for recording the information signals O and 1, where T is the duration of the clock interval, while writing an information O forms one pulse, and when recording the signal informational 1 - three pulses, when recording informational O, the pulse forms 0.5 T from the beginning of this interval when this informational O is followed in a sequence consisting of O, 0.5T when it follows this interval after the info mation 1 (at the junction 100.,.). In the interval 1.5, the second and third pulses are formed through 0.9 T and 1.3 T from the beginning of this interval, and the first pulse in the information interval 1 is set through 0.3 T and 0.4 T after the information O and 1, respectively. The duration of the clock period T is chosen from the conditions T T0 16 / V, where V is the speed of movement of the recording medium, and g is the working gap of the magnetic head.

Figure 1 shows the block diagram of the device; figure 2 - timing charts of the signal.

The device contains a pulse generator 1, a counter 2, a multiplexer 3 connected via a shaper 4 bipolar pulses to an output data bus 5. The shift register 6 is connected through the elements HE 7-9, the elements AND 10-12 and the element HE 13 with the corresponding inputs multiplexer 3, the output clock bus 14 and the input information bus 15 are connected to the corresponding inputs of register b and multiplexer 3, with the free inputs of which are connected to the bus 16 of zero potential.

The device works as follows.

Counter 2 (controlled with division factors 15 and 10) operates in the pulse counting mode generated by the generator. The high-count signal Az of the counter bit of counter 2 is a clock signal for an information source (not shown), the information signal from which via bus 15 is fed to the input of trigger 6. The signal

from the trigger input is fed alternately to input 1 (signal Xi), output (X2) and output 3 (Xs) of the trigger.

Depending on the state of the signals Xi-Xs, elements 10-12 coincidence form signals to the inputs of multiplexer 3, which forms a pulse sequence (signal B), which generates pulses of alternating polarity of the signal B, coming through bus 4 to the magnetic

a head for recording on magnetic media (the head and the carrier are not shown).

In the interval of informational O (the conversion factor of counter 2 is 10) it forms one pulse through 0.5 T from the beginning of this interval, following the informational O after the informational 1 and before the informational O, in this interval (after the interval 1). In the interval 1.5 T form the second and third

pulses through 0.9 T and 1.3 T from the start of the interval.

The first pulse on the information interval 1 is formed through 0.3 T and 0.4 T when this interval is followed after the information intervals O and 1, respectively (table and figure 2, C).

The table shows the formation of recording pulses.

At specified intervals follow

recording pulses the minimum length of magnetic prints is 0.4 T at T T0 1 (5 / V, where V is the speed of movement of the recording medium; b is the working gap of the magnetic head.

Variation of formation intervals

the first pulse in the interval of 1.5 T and the pulse in the interval of 1 T provide correction for the offset of the null transitions of the playback signal (plot 2, D), i.e. intersymbol significantly reduced

distorted reproduced signals.

The playback signal (Fig. 2, D) is two-interval with time intervals of 1 T and 1.5 T for information signals O and 1, respectively, with a decoding window of 0.5 T. This signal has self-synchronization, and its minimum period carries two bits of information . The selection of information and sync signals is carried out on the null transitions of the reproduced signal.

Recording can also be carried out without first demagnetizing the magnetic recording medium, i.e. according to the old signal.

The technical and economic effect is to increase the recording density: (1) by increasing the information capacity of the implemented method from 1 bit / period to 1/3 bit / period (worst case), i.e. 1.33 times (33%) higher; (2) by changing the conditions for implementing the recording mode — reducing the clock period T T0 1 (5 / V, (instead of T 1.5 5 / V), i.e., 1.5 times (50%). Overall increase Record density in 1.33 l 1.5 2 times compared with the known.

The device provides a density of up to 450 bits / mm (at a tape speed of 47.6 mm / s and a recording frequency of 17 kHz), i.e. 4.5 times more.

Claims (1)

The invention is a device for magnetic recording of digital information, containing an input information bus, a pulse generator, the output of which is connected to the counter input of the counter, the outputs of the bits of which are connected to the address inputs of a multiplexer, the output of which is connected through a bipolar pulse shaper in the form of a series-connected counter. trigger and pulse generator alternating polarity to the output data bus, output clock bus connected to the output of the higher bit of the counter and a zero potential bus connected to the multiplexer input, characterized in that, in order to increase the density, four HE elements, three AND elements and a shift register are introduced into it, the output clock and input information bus are connected to the clock and information inputs of which , while the first output of the shift register is connected to the control input of the counter, through the first element NOT and the first element I to the fourth input of the multiplexer, through the third element I to the sixth input of the multiplexer connected by black Without the fourth element NOT with its seventh input and through the second element I to the fifth input of the multiplexer, the second output of the shift register is connected to the other inputs of the first and second elements I, to the tenth and fourteenth inputs of the multiplexer through the second element NOT to the second input, The third element is And, the third input of which is connected via the third element NOT to the third output of the shift register, and the free inputs of the multiplexer are connected to the zero potential bus. Note. X is an indifferent state 1ST 1ST about J it Fig, 2.