SU1425767A1 - Device for shaping a stretch of inclined line on crt screen - Google Patents

Abstract

The invention relates to automation and computing and can be used in devices for precision display of graphic information on a screen of a cathode ray tube. The purpose of the invention is to increase the speed of the device. The device contains the first register 1, adders-subtractors 2 and 3 on the coordinates X and Y, the first 4 and second 11 switches, the second 7 and third 9 adders, the first 6 and second B registers, the first 10, second 15, third 16 and fourth 22 comparison units, first 12, second 18 and third 20 elements AND, counters 13 and 14 along the coordinates X and Y, element OR 17, generator 19 pulses, trigger 21 with corresponding connections. Codes of coordinates of the beginning and end of the sloping line are entered in -register 1. In subtractors 2 and 3, the values of increments in X and Y are calculated. Depending on the sign of the increments, the first 4 and second I1 switches commute increments to the inputs of the first 5 and the second 7 adders and clock pulses from the output of the second element I 18 to the clock inputs of the counters 13 and 1.4, where the values of the intermediate coordinates of the line are calculated, thereby achieving the performance of the device. 1 il. i (L

Description

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The invention relates to automation and computer technology and can be used in devices for precision display of graphical information on a screen of a cathode ray tube (CRT).

The purpose of the invention is to increase the speed of the device.

The drawing shows the functional diagram of the device.

The device contains the first register 1, the adder-reader 2 on the X coordinate, the adder-subtractor 3 on the Y coordinate, the first switch 4, the first adder 5, the second register 6, the second adder 7, the third register 8, the third adder 9, the first block 10 compare the second switch 11, the first element AND J2, the counter 13 by the X coordinate, the counter 14 by the Y coordinate, the second comparison block 15, the third comparison block 16, the OR element 17, the second And 18 element, the pulse generator 19, the third And 20 element, trigger 21, fourth comparison block 22.

The device works as follows

In register I, codes of the initial and final coordinates of the vector are written on the X and Y axes. Initial codes: coordinates the census to counters 13 and 14. Displaying a vector on a CRT screen (not shown) of the vector can be done by connecting the outputs of counters 13 and 14 directly through The DAC to the deflecting system of a CRT or through a graphic memory, the output of which through the DAC is connected to the diverting system of a CRL. When the device is connected to a graphic memory, the outputs Ex. The outputs Y of the counters 13 and 14 are connected to the address memory bus and, if there is an active level on the resolution bus (Output ratio), at the rate of the signal (Output signal) from the output of the second element And 18-, the levels of the logical 1 to the generated addresses, i.e. the enable signal can be connected to the memory data bus.

The codes of the initial and final coordinates X and Y are fed to the inputs of the szgmmatorov-subtractors 2 and 3, respectively, to perform the subtraction operation in order to find the module and the sign of the projection of the vector on the x-axis

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The codes of the modules of the projections of the vector are fed to the switch 11, and the signs of the projections are transferred to the counters I3 and 14 to set the addition or subtraction modes on these counters, the registers 6 and 8 are zeroed by communication with the output of the trigger 21, after which the latter changes its state and gives the resolving potential of the beginning of the formation of the segment, and also opens the second element I 18 and from its output the pulses of the generator 19 of pulses come.

When constructing a vector ranging from 0 to 45, the third comparison unit 16 changes the control potential ja to the inputs of the first 4 and second 11 switches. As a result, the first switch 4 switches the frequencies at the inputs of counters 13 and 14. In this case, the frequency from the output of the pulse generator 19 is fed through the first switch 4 to the input of counter 13, and to the input of counter 14 through the first switch 4 a signal is output from the third element And 20 The second switch 11 connects the input of the adder 5 with the output of the adder-subtractor 3 and the input of the adder 7 and 9 - with the output of the adder-subtractor 2.

The fourth comparison block 22 realizes the comparison of the output of the first adder 5 with the output of the adder 9. When building a vector from 45 to 90 according to the potential from the output of the third comparison block 16, the first switch 4 transmits pulses from the output of the generator 19 pulses to the counter input of counter 14. On the counting the input of the counter 13 through the first switch 4 passes pulses from the output of the third element I 20. The input from the adder 5 through the second switch 1I receives a signal from the output of the adder-subtractor 2, and to the input of the adder 7 receives a signal through the second Switch 1 from the output of the adder-subtractor 3.

Thus, the invention improves the speed of the device due to the fact that the calculation of the following coordinate values is performed in one clock of the pulse generator 19.

Claims (1)

Invention Formula Device for forming a segment of an inclined line on the screen of a cathode ray tube (CRT), containing the first register, the adder-calculator on the X coordinate, the adder-subtractor on the Y coordinate, the first switch, the counter on the X coordinate, the counter on the Y coordinate , the first comparison unit, the second comparison unit, the OR element, the first And element, the shots generator, the second And element, the trigger whose output is connected to the first input of the second And element and is the output of the device for the beginning of formation of the device segment, the output of the impulse generator It is connected to the second input of the second element, the output of which is connected to the first informational input of the first switch, the first and second outputs of which are connected to the clock inputs of the counters, respectively, by coordinates X and Y, the first output of the first register is connected to the first information input of the subtractor on the X coordinate and to the information input of the counter on the X coordinate, the control input of the record of which is connected to the first output of the adder-subtractor on the X coordinate, the second information input of which is also the first The first input of the comparison unit is connected to the second output of the first register, the third output of which is connected to the first information input of the adder-subtractor on the Y coordinate and to the information input of the counter on the Y coordinate, the control input of which is connected to the first output of the adder-subtractor on the coordinate Y, the second information input of which and the first input of the second comparison unit are connected to the fourth output of the first register, whose information and controllers in} are each inputs of coordinate codes nat and inputs of recording pulses of the device, the first outputs of the counters in the X and Y coordinates are connected respectively to the first and second inputs of the OR element, the third input of which is connected to the output of the first element AND, the first and second inputs of which are connected respectively to the outputs of the first and second blocks compare you 0 five 0 5 "with 0 40 45 50 the element's travel OR is connected to the counting trigger input, the second counter output of the X coordinate is connected to the second input of the first comparison unit and is the output of the X coordinate code of the device, the output of the Y coordinate code of which is the second counter output of the Y coordinate connected to the second input of the second Comparison unit, which is related to the fact that, in order to improve the device speed, it contains the second switch, the first, second and third adders, the second and third registers, the third and fourth blocks of the comparison, the third element The output of which is connected to the second information input of the first switch and to the control input of the recording of the third register, the output of which is connected to the first information inputs of the second and third adders, the second information inputs of which are connected to the first output of the second switch, the first information input of KOTopqro and the first input of the third comparison unit connected to the second output of the adder-subtractor on the X coordinate, the second output of the adder-subtractor on the Y coordinate is connected to the second input of the third block compared and to the second information input of the second switch, the output of the third comparison unit is connected to the control inputs of the first and second switches, the second output of the second switch is connected to the first information input of the first adder, the output of which is connected to the information input of the second register and the first input of the fourth block the comparison, the output of which is connected to the first input of the third element I, the second input of which and the input of the recording control of the second register are connected to the output of the second element AND and are pulses Exit accompaniment device coordinates, the second information input of the first adder is connected to the output of the second register, reset the second and third registers inputs connected to the output of the flip-flop, the third output of the adder is connected to the second input of the fourth comparison unit, the second adder output is connected to of information insulating input of the third register. /