RU1795509C - Device for representing graphical information - Google Patents

Abstract

The inventive device contains 1 clock generator (1), 3 counters (2, 6,12), 2 comparison blocks (4,5), 1 memory block (3), I buffer memory block (7), 1 element (8), 1 element AND (10), 1 element OR (11). 1 video control unit (9). 1-11-12-3-4-8-9.1-9.1-12-7-5-8. 5-10-11.3-7.3-4-10.1-2-3.1-7.1-6-4.6-5. 1 ill.

Description

The invention relates to the field of computer engineering and automation and can be used to display graphical information on the screen of a cathode ray tube with a raster image scanning method.

The purpose of the invention is to expand the scope of the device by displaying curves corresponding to non-monotonic functions having several intersection points on the same side of the raster.

The drawing shows a functional diagram of the device.

The device comprises a sync generator 1, a first counter 2, a memory block 3, comparison blocks 4 and 5, a second counter 6, a buffer memory block 7, an element 8 DISAPPEARANCE, a video monitoring unit 9, an AND element 10, an OR element 11, and a third counter 12 .

If the maximum possible number of intersections of the graph with one side of the raster is denoted by N, then for a raster consisting of m rows and n columns, the volume of memory block 3 will be mxn cells, and the number of bits of each cell will be logaN. Accordingly, the buffer memory unit 7 contains N cells, and the resolution of the third counter 12 will be logaN.

The device operates as follows.

From the first output of the clock 1 to the corresponding input of the video control unit 9 receives the horizontal and frame synchronization signals. The second and fourth outputs of the clock 1 are connected to the clock inputs of the counters 2 and b, which carry out the vertical and horizontal sampling of the raster, respectively.

In accordance with the line number at the input of the memory unit 3, the coordinates of X points belonging to this line appear, moreover, the choice of one of N cells is determined by the contents of the third counter 12, the output of which is connected to the second address input of the memory unit 3 and, in addition to the address input of block 7 of the buffer memory. Information about the horizontal coordinate points of the previous line of the raster is entered into block 7 of the buffer memory during the reverse stroke of the line using a series

of N pulses arriving at its recording control input from the second output of clock 1. With a certain time delay, the same series of pulses through

OR element 11 is fed to the input of the third counter 12, which is reset by a signal from the sixth output of the clock at the beginning and end of the reverse stroke of each line.

Codes of coordinates X from the outputs of block 3 of memory and block 7 of buffer memory are supplied to the first inputs of blocks 4 and 5 of comparison, respectively, and compared with a linearly increasing code from the output of counter b

horizontal sampling. When the contents of this counter reaches the value of the smaller of the coordinates from the memory unit 3 and the buffer memory unit 7, the output of the corresponding comparison unit displays the level of a logical unit, which leads to the appearance of a signal at the output of the UNAQUALITY 8 element allowing the calculation of raster points on the screen of the video control unit 9 in

current scan beam positions. After the contents of counter 6 reach the value of the largest of the coordinates, another comparison unit is activated, and a single signal from its output sets low

the level at the output of the UNAQUALITY 8 element, which prohibits highlighting of raster points. This completes the process of displaying a horizontal line segment defined by a pair of coordinates in block 3

memory and block 7 buffer memory. When unit levels appear at the outputs of the comparison blocks 4 and 5, the AND element 10 is triggered, and the signal from its output through the OR element 11 enters the input of the

counter 12, increasing its contents by one. In this case, a new coordinate pair is selected from the memory block 3 and the buffer memory block 7, defining the next segment of the current line to be displayed.

The invention allows to expand the scope of the device by visualizing more complex curves characterized by a non-monotonic change in the displayed parameters, i.e.

the need to display on the display screen many horizontal segments in each line of the raster.

Claims (1)

The claims A device for displaying graphical information comprising a video monitoring unit, the clock input of which is connected to the first output of the clock generator, the second output of which is connected to the clock input of the first counter, the output of which is connected to the first address input of the memory unit, the output of which is connected to the first input of the first block comparison to the information input of the buffer memory block, the recording control input of which is connected to the third output of the clock generator, the fourth output of which is connected to the clock input of the second th counter whose output is connected to a first input of a first and a first input of the second comparator unit, the outputs of which are connected to the inputs of the element are unequal, the output of which is connected to video input of the video control unit, the output of the buffer memory unit is connected to the second input of the second comparison unit, which means that, in order to expand the scope of the device by displaying curves corresponding to non-monotonic functions having several intersection points with the same with a raster line, an AND element, an OR element, and a third counter are inserted into it, the output of which is connected to the address input of the buffer memory unit and the second address input of the memory unit, the inputs of the AND element are connected to the outputs of the first and second comparing the locks, and the output AND gate connected to the first input of the OR gate, a second input coupled to the fifth output clock, a sixth output which is connected to the reset input of the third counter, the clock input of which is connected to the output of the OR gate.