SU1582202A1 - Device for information search on tape record carrier - Google Patents

Abstract

The invention relates to the accumulation of information, namely, devices for searching information on a tape recording medium. To reduce the search time for information placed on the carrier at regular intervals, logical elements OR 16, 18 and timer 17 are introduced into it. 2 Il.

Description

12

ate

00

Yu

HS

about

N5

The invention relates to the accumulation of information, in particular, devices for searching information on a tape recording medium.

The purpose of the invention is to reduce the search time for information placed on a tape recording medium at regular intervals.

Figure 1 shows the functional diagram of the device; in fig. 2 shows a possible algorithm for the operation of the device.

The device contains a drive unit 1, a tape mechanism 2, a playback unit 3, a first register 4, a second comparison block 5, a second register 6, a decoder 7, a counter 8, a first comparison block 9, an information input bus 10, a multiplexer 11, an input bus 12 control signal, block 13 additional registers, output bus 14, block 15 of memory, the first element OR 16, the timer 17 and the second element OR 18.

The output of the drive unit 1 is connected to the input of the tape drive mechanism 2, the output of which is connected to the input of the playback unit 3, the output of which is connected to the input of the decoder 7 and the input of the first register 4, the output of which is connected to the first input of the counter 8, the output of which is connected to the second input of the first unit 9 comparison, the third inputs of the counter 8 are connected to the first outputs of the block 13 additional registers connected by the second, third, fourth, sixth, seventh and eighth outputs, respectively, with the second input of the second register 6, the second input th. the first register 4, the input of the drive unit 1, the device output bus 14, the sixth input of the multiplexer 11 and the second input of the memory block 15, the first input of the second register 6 is connected to the input information bus 10, the output of the second register 6 is connected to the second input of the second block 5 comparison, you code of memory block 15 is connected to the input of block 13 of additional registers. The first input of memory block 15 is connected by the z output of multiplexer 11 connected by the first, second, third and fourth inputs respectively to the output of the decoder 7, the output of the second comparison block 5 , Output of the first comparing unit 9 and the input bus 12 of the control signal, the first input

0

five

0

five

0

The first element OR 16 is connected to the output of the decoder 7, the second input of the first element OR 16 is connected to the fifth output of the additional registers block 13, the output of the first element OR 16 is connected to the input of the timer 17, the output of which is connected to the fifth input of the multiplexer 11 and the second input of the second element OR 18, the first input of which is connected to the output of the decoder 7, the output of the second element OR 18 is connected to the second input of the counter 8, the first input of which is connected to the first input of the first comparison unit 9, the output of the counter 8 is connected to the first input The second unit 5 is a comparison.

The device works as follows.

Information retrieval on a tape recording medium using the proposed device is as follows.

The search for the required address on the tape recording medium begins after the signal of logical 1 appears on the input bus 12 of the control signal. In the second register 6, the signal from the input bus 10 of information is entered into the code of the address sought. Then, a signal from block 13 of additional registers arriving at block 1 of the drive, the tape drive mechanism 2 begins to move the tape recording medium before block 3 of the reproduction. The information from the output of the playback unit 3 is fed to the input of the first register 4 and to the input of the decoder 7. If the information from the output of the playback unit 3 is decrypted

as the address

then the signal from the block

13 additional registers, this information is entered into the first register 4. After this, the information from the output of the first register 4 is recorded by the output from the block 13; additional registers are entered into the counter 8. After reading the next address from the tape media, a signal appears again at the output of the decoder the second element OR 18 modifies the counter 8. In addition, the signal from the block 13 of additional registers will read the code of the read address from the output of the playback block 3 into the first register 4. If after this the course of

515

If the first comparison block 9 shows a mismatch signal, then a new address code will be written to the counter 8 according to the signal from block 13 of additional registers. The above actions will be repeated until the contents of counter 8 match the address code read from the tape media. Such a sequence of actions excludes the possibility of starting a search from a distorted address or from the place on the tape media where the normal growth of addresses is violated (for example, due to the disappearance of an address group due to a carrier defect). If after reading the second address from the tape media and writing it to the first register

4 a coincidence signal is present at the output of the first comparison block 9, then the output of the second block is analyzed

5 compared. One of three situations is possible: the first one, when the contents of the counter 8 and the second register 6 coincide, then the required address is found: from block 13 additional registers to the output bus

14, a search end signal is issued; second, when the contents of counter 8 are greater than the contents of the second register

6, in this case, the signals from block 13 of additional registers are used to reverse the tape mechanism 2 and change the direction of modification of counter 8, with the result that the search for the desired address continues in the direction of decreasing addresses; and a third situation, when the contents of the counter 8 are smaller than the contents of the second register 6, in this case the search continues in the same direction as the addresses increase.

If during the search for the desired address at the output of the second comparison unit 5, a match signal appears, and the output of the first comparison block 9 contains a mismatch signal, then from block 13 of additional registers an output signal 14 will generate an Error signal.

In the process of searching for the desired address, together with the outputs of the first 9 and second 5 comparison blocks, the output of timer 17 is analyzed. The timer 17 is started through the first element OR 16 by a signal from the decoder output

7, After starting at the timer output

2026

17 sets the logic level to 1. Signals that will appear at the output of the decoder 7, when decoding each next address, restart the timer 17 so that its output will always have a logic level 1. If for some reason

JQ blowing address on the tape is missing, then after the permissible interval of time, during which the address of the next array should have appeared,

5 The output of timer 17 is a zero signal, which through the second element OR 18 modifies counter 8. Restarting timer 17 in this case is performed by signal 20 from the output of block 13 additional registers through the first element OR 1 (After that, the output of the second block 5 is analyzed If there is a coincidence signal at its output, then from block 13 of additional registers a signal will be output to output bus 14. There is no array. If the output of the second comparison block 5 is at 3 (there is no signal After that, the search for the desired address continues.

Claims (1)

Invention Formula ; A device for searching information on a tape recording medium comprising a drive unit connected via a tape drive mechanism to an input , the playback unit connected by the output to the interconnected input of the decoder and the input of the first register connected by the output to the interconnected first 5 to the input of a pulse counter connected with the output to the first input of the first comparison unit and the first input of the second comparison unit connected by an output to the first input of a multiplexer connected by a second input to the output of the first comparison unit, a third input to the output of the decoder, the fourth input to the control bus and output through the memory unit to the blog input of registers connected by the first output to the output bus, the second output to the second input of the pulse counter, the third output to the control input of the second register, input to the information bus and the output to the second input of the first comparison unit, the fourth output to the control input of the first register, the fifth output to the input of the drive unit, the sixth output to the control input of the memory unit and the seventh output to the fifth input of the multiplexer, different by the fact that, in order to reduce the search time for information placed on a tape recording medium at regular intervals of time, it is entered in succession the first OR element, the timer and the second OR element connected by the output to the third input of the pulse counter connected to the second input of the second comparison unit, the first OR element connected by inputs to the decoder output and the eighth output of the register block, connected to the sixth output the input of the multiplexer, and the second element OR is connected by one of the inputs to the output of the decoder. Tatlfte / i Mtl