SU1453440A1 - Device for displaying information on crt screen - Google Patents

Abstract

The invention relates to automation and computing and can be used in devices for outputting alphanumeric and graphic information on a screen, CRT. The purpose of the invention is to increase the speed of the device, which is achieved by introducing a preemptive interrupt block and corresponding functional relationships, which allows the information to be written into the main memory during the entire time allowed for a recording free of the reading process and displayed on the screen CRT rapidly changing images. 1 hp f-ly, 3 ILO: SO

Description

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The invention relates to automation and computing and can be used in devices for outputting alphanumeric and graphic information on a screen of a cathode ray tube (CRT).

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

Fig. 1 is a block diagram of the device; Fig. 2 is a block diagram of a preemption block; FIG. 3 is a block diagram of a shaper jm-equal to the signals.

The device contains a conjugation unit 1, a sign-forming unit 2, for example, consisting of a generator of 3 vectors, a generator of 3 symbols, a generator of 3 circles, a second register 4 (reading), a switch 5 consisting of a group of keys 6, + 6, an operative memory unit 7 (accumulator) consisting of a decoder 8 and memory 9, a first register 10 (read addresses), a video signal generator 11 connected to a cathode ray tube modulator 12 (CRT 13, counters 14 and 15 sweep the coordinates X and Y, respectively, the third register 16. (light pen), specifying the generator Op 17 and block 18 preemption "

The priority interrupt unit 18 comprises a control signal generator 19, -19m and an AND element 20.

Shaper 19 control signals contains a trigger 21, the element AND-NOT 22, the inverter 23, the element OR 24 the element AND-NOT 25, the element 26 delay, the elements AND 27 and 28, the inverter 29 and the element AND OZ

The device works as follows

Each elementary point of the CRT 13 screen (monitor TK) corresponds to a group of cells of block 7 (accumulator) where information about the color and brightness of the point is stored. Thus, there is a one-to-one correspondence between the position of the elementary point on the TV monitor screen and the address of the accumulator 7 „

The number of elementary points is. It is a ratio, where n is the number of line layout elements, m is the number of lines in the frame.

Information comes from a computer (not shown) in the form of 16-bit words.

in block 1 (interface) “The formats of the transmitted words are as follows; the first three bits define the type of directive given to the device Display symbol, Display vector, Display circle, Set coordinate, Fill feature word, Read register, the fourth bit controls writing and erasing information in drive 7 about the remaining bits used to set the code the displayed symbol, the values of the orthogonal components of the vector, the radius of the circle, the brightness and the color of the displayed element, and T.Pe

Informing unit 2, in accordance with the received directives, enters information into block 7 via keys and highway 31. In the case of readiness to write information, unit 2 requests permission from block 18 for access to drive 7, If drive 7 is read-free or free, Block 18 aa gives the permission signal to access drive 7 and opens the keys with the same signal to transmit information to trunk 31. The same signal is used in the request signal block. In parallel with the recording, information is being read from storage device 7 and playing it on the TV monitor screen.

The reading is carried out in groups of 64 cells from each layer of the accumulator 7. A periodic signal with a period of 5 ISS is removed from the counter 14 and used as a request for access to the accumulator for block 18. In accordance with the accepted service discipline, block 18 organizes reading of information from drive 7..

In order to obtain a stable image, the reading must be carried out strictly synchronously with the movement of the beam of the TV monitor. For this purpose, the reading process is given the highest priority, and the request to block 18 for reading information is set in advance. The advance of the request relative to the start time of the reading is one cycle of operation of the accumulator 7. In this case, if at the time of the request, the accumulator 7 is occupied by recording information, then the recording. continued until its natural ending, and the new

the write cycle can begin only after the reading of information from accumulator 7 is completed. Block 18 operates as follows. Suppose that accumulator 7 is free and block 2 requests access. In this case, zero potential is applied to one of the inputs of the AND-22 elements and 27 Therefore, the element And 27 is closed, and on one of the inputs of the elements AND-NOT 25 and And 30 - single potentials. This information of the driver 19 is blocked, and the signal from block 2 is fed to the input controller of the write-read driver,; Teo to one of the inputs of the elements OR 24 and AND 20, Since the drive 7 is free and there is no signal to prevent writing to the input blocking a record, then at the output of the element I 20

There is a high potential that enters the AND-HEY elements 25 and through the delay element 26 and the AND element 30 sets the trigger 21 to the unified state. At the same time, at the output of the AND 28 element, a signal appears that enters the drive 7 as the Start signal, which from the output of the AND-NE element 25 enters the inputs of the AND elements 27 and AND-NOT 22 and prohibits the distribution of the read control signal from others source

- In this case, the corresponding outputs of block 2 are connected via switch 5 and trunk 31 to the input of accumulator 7, which, with the delaying 35 control inputs of the sign-forming unit and the first register, the first output of which and the outputs of the first group of the sign-forming unit are connected respectively to the first information

which is necessary to end the trans. Q & a input and information inputs of the salable process in line 31, relative to the Start signal, form a timing diagram for recording information in memory 9 ,, If at the moment of recording information in block 7 a service request is received in block 18 via inputs 32-35 , then due to the fact that; on the element AND-NO 22 there is zero; signal propagation potential

switch groups whose outputs are connected to the address and information inputs of the RAM block, the first output of which is connected 45 to the inputs of the video signal generator and the second register, the output of which is connected to the information input of the interface block, the address input which is connected to the output of the third register

The request is blocked until the window of information is on Ie, the inputs of which are in line with the process of recording in block 7, if they are connected to the first outputs of the counters

the request on input 36 of block 18 comes later than access is provided to any other input of block 18, then the request on input 36 is blocked by the AND-NOT element 25, since its friend

input potential zero I

Block 18 works similarly when

on the appearance of a signal request for any

sweep in X and Y coordinates, the control input of the third register is in the control input of the devices 55; the output of the video signal conditioner is connected to the modulator of the electron beam, the deflection system of which is connected to the second outputs of the coordinate sweepers

Behind .

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the entrance. Signal Prohibit recording is stopped for a period of reading information in block 7 and its leading edge is ahead of the signal. Reading by one operation cycle of block 7 This signal by means of AND 20 blocks the signal distribution circuit Response and at the output of AND 20 will be 10 left the potential, with the output of the element IS-NOT 25 will remain in the single state, the trigger 21 - in the zero state and the start signal will be blocked

15 If the trigger 21 before the arrival of the next signal The answer is in the single state, then when the specified signal appears, it will go to the zero state and will remove the signal

20 Resolution from the corresponding input of the switch 5.

The proposal improves the speed of recording information by providing the process of recording the entire time

25 is free of reading process, which allows displaying CRT images on the screen quickly.

Claims (2)

Invention Formula thirty 1 o A device for displaying information on the screen of a cathode ray tube containing an interface unit whose outputs are connected to 35 control inputs of the sign-forming unit and the first register, the first output of which and the outputs of the first group of the sign-forming unit are connected respectively to the first information input and the information inputs Q „th input and information inputs switch groups, the outputs of which are connected to the address and information inputs of the RAM, the first output of which is connected 45 to the inputs of the video signal conditioner and the second register, the output of which is connected to the information input of the interface unit, the address input of which is connected to the output of the third register.  information I whose inputs are connected to the first meter outputs sweep along the X and Y coordinates, the control input of the third register is the control input of the device, 55 the output of the video signal conditioner is connected to an electron beam modulator, the system of which is deviating. the swarm is connected to the second outputs - the sweep counters by coordinates five X and Y, the counting input of the sweep counter on the Y coordinate is connected to the overflow output of the sweep counter on the X coordinate, the counting input of which is connected to the output of the backward generator, the third outputs of the X and Y coordinates are connected to the second and third information inputs respectively - a mutator, distinguished by the fact that, in order to improve the speed of the device, it contains a priority preemption block, the recording control inputs of which are connected to the outputs of the second group of the sign of the fmirth block, the inputs readout control — respectively, with the second output of the first register and the fourth output of the sweep counter along the X coordinate, the fifth output of which is connected to the write lock input of the priority interrupt unit, the overwrite control input of which is connected to the second output of the operational memory, and the group outputs and output - according to the corresponding control inputs of the switch and the control input of the operating memory block 5 5 2. The device according to claim 1, characterized in that the priority interrupt unit contains an AND element and control signal drivers, the first output of each The ice of the control signal generator, besides the first one, is connected to the clock input of the previous control signal generator, the first output of the first control signal generator is connected to the first input of the element, and the second and third outputs of the control signaling signals are the group outputs and the block output , the fourth output of each previous control driver, except the last one, is connected to the information input of the subsequent control driver, the output of the last control signal the control signal gates are the output of the block, the second and third inputs of the OR element are, respectively, the rewrite control input and the block write input of the block, the write control inputs and readings of which are the control inputs of the controllers