SU807368A1 - Device for displaying information on crt screen - Google Patents

Description

(54) DEVICE FOR DISPLAYING INFORMATION ON SCREEN OF ELECTRON BREAD TUBE

c) large hardware costs, i.e., the presence of four counters that generate synchronization signals, three address counters and a divider;

d) inefficient use of RAM, for example, if the text line is not completely filled, then the remaining spaces must be filled with a space code in the memory.

The aim of the invention is to simplify the device and expand its scope by providing display of graphic information, changing characters, their number per line and the number of lines in the frame.

The goal is achieved by the fact that the device contains a generator, a point counter, a television line counter, line and frame scanners, an RAM block, an address counter, a decoder block and a fixed memory, and a shift register, the generator output being connected to the first input of the point counter, the first output of which is connected to the control input of the shift register, the intermediate outputs of the television line counter are connected to the control inputs of the decoder unit and the fixed memory, e outputs of which are connected to informational inputs of the shift register, the output of which is connected to an electron-beam tube, outputs of an address counter are connected to the inputs of the main memory unit, and outputs of the horizontal and frame sweepers to the electron-beam tube, additional horizontal and frame frequency dividers are added, a register the starting address of the lines, the register of the starting address of the pages and the control unit for changing the address, the outputs of the address counter are connected to the inputs of the register of the starting address of the pages and to To the first inputs of the register of the starting address of the lines, to the second inputs of which are the outputs of the register of the starting address pages, and the outputs of the register of the starting address of the lines are connected to the inputs of the address counter, the outputs of the operational memory block are connected to the control unit for changing the address, the control input of which is connected to the second the output of the point counter, the information outputs of the address change control block are connected to the information inputs of the descrambler block and the fixed memory, and the control output is connected to the first control input of the counter a The address to the second input of which is the output of the horizontal frequency divider, which is also connected to the first input of the TV line counter, to the input of the horizontal scanning signal generator and to the input of the frame frequency divider, and to the second input of the point counter and to the second input of the TV line counter are connected the outputs of the descrambler unit and the fixed memory, and the output of the frame frequency divider is connected to

the input of the framing signal generator and to the first control input of the register of the initial address of the pages, to the second input of which we connect the control input, and the output of the TV line counter overflow to the control input of the register of the starting address of the lines.

This method of construction allows you to expand the functionality of the device, since a change in the conversion factors of the circuits determining the linear dimensions of familiarity on the screen (point counter and television line counter) no longer affects the operation of the vertical and horizontal scanning circuits (divisors of the vertical and horizontal frequencies) and schemes of the address part (address system compiler, register of the starting address of lines, register of the starting address of pages). The sizes of the characters are specified by codes in the RAM block, or by commands from the control panel, which are decrypted in the decoder block and the fixed memory.

and control the conversion factors for points and television lines.

The flexibility of the device is increased, since the various codes that control the layout of information on the screen can be decrypted by the address change control block and control the operation of the address counter, for example, it is possible to store in the memory block not the empty space codes on the screen, but their number, the same applies to any repeated characters. The device can work with any arbitrary number in the line determined by the frequency of the point counter operation, which can be operatively controlled.

The hardware costs are reduced, because instead of three address counters and one divider, one address counter and two registers are used, which are simpler devices compared to counters, the character counter with the logic block and the text line counter are also replaced by simpler dividers. The capacity of the RAM block is saved, repeated characters and spaces are written in the form of repetition codes. If the text line is not completely filled up, then instead of spaces in the memory, it is enough to write the line feed code, which is decrypted by the address change control block and controls the operation of the address counter.

The drawing shows the block diagram of the arrangement.

The device contains a clock frequency generator 1, a counter of 2 points, a counter of 3 television lines, a horizontal divider, 4 and a frame frequency of 5, shapers of lowercase 6 and frame 7 sweeps, block 8 of operational memory, block 9 of control for changing the address, block 10 of the decoder and constant memory, shift register 11 CRT 12, the address counter 13, the register 14 of the starting address of the lines, the register 15 of the starting address of the pages.

The device works as follows.

The generator 1 produces pulses of the reference frequency FO, which are fed to the input of a 2-point counter and a divider 4 of the horizontal frequency. From the outputs of the 2-point counter, the FT signals are removed — the frequency of changing the elementary point on the screen and E, the frequency of changing the characters that determine the horizontal dimensions of the characters displayed on the screen. The output of the splitter 4 line frequency is connected to the divider 5 frame frequency. These dividers, together with the corresponding formers 6 and 7, provide standard TV signals of the standard Getter and personnel RC of scans for the CRT 12. Signals from the output of the splitter 4 horizontal frequency with the frequency Retr arrive at the input of the counter of 3 television lines, on the intermediate outputs in binary code the numbers of the scanned lines appearing in the matrix of the sign appear. From the overflow output of the 3 television lines counter, a signal is received that determines the frequency of changing the text-Pc lines, p. T. The signals of this counter determine the vertical size of the symbol.

Thus, in the proposed device, there are two independent synchronization paths: one - controlling the operation of the address part that determines the sequence and duration of the display of characters on the CRT screen (2 point counter and 3. TV lines counter), and the second - generating standard horizontal and horizontal signals. frame scan for CRT (dividers 4 and 5 and shapers 6 and 7).

Moreover, the restructuring of the address part schemes does not affect the operation of the television synchronization schemes. Sequential polling of the addresses of the block 8 is performed by the counter 13 of the address. It is controlled by the block 9 of managing the change of the address to which the clocking signals with the FC frequency from the 2 point counter are received. Information from the outputs of block 8 through the control unit for changing the address of the rio comes in block 10 of the de-divider and the permanent memory, where the configurations of the displayed characters and codes that control their sizes on the screen of the CRT 12 are stored. To the control inputs of the unit 10 of the descriptor and the permanent memory From the 3 TV lines counter, the line number is included in the matrix of the displayed character. A shift code is written to the shift register 11, the units of which define the light points of the character on a given television line. The shift register 11 is sequentially scanned at a frequency FT. The control codes from the outputs of the descrambler unit and the unused memory are fed to the control inputs of the 2 point counter and the 3 TV lines counter, as a result of which the tracking frequency of the Py signals. F and. „„. When displaying a line of text on the screen

it is necessary to ensure that the address counter returns to the first address of this line as many times as there are TV lines in the vertical matrix of the sign. For this, the starting address of the text line is written with

the register 14 of the start address CTpoKij, with the signal 6t1.geg, once at the beginning of a line of text, and then at the end of each of the television lines constituting this line of text, is rewritten from register 14 to the counter 13 of the address with the signal FCTJ, thereby providing

required return to the first address of the displayed string of characters. The starting address of the displayed text page is stored in register 15 of the starting address of the pages. If the volume of block 8 exceeds the number of characters displayed on the screen in one frame, then using register 15, the starting address of the pages, the contents of the RAM block can be viewed either in the scrolling mode or in the smooth scrolling mode, which are specified with

0 remote control.

In the flipping mode, the contents of the counter 13 of the address with the FK signal are entered into the register 15 of the initial address of the pages and are rewritten into the register 14 of the starting address of the line, thereby preparing the cell address of block 8, from which the output of the next page of text begins.

In the smooth scrolling mode, the starting address of the page is rewritten from the counter 13 of the address according to the coincidence of the signals with the control signals at the control input of the register 15, the frequency of which determines the speed of information movement on the screen.

The address change control block executes commands that control the expansion of information recorded in the block in a compressed form, such as line feed, tabulation, repetition, etc.

The line break command is used if the text string is not completely filled. At this command, the promotion of the address counter is stopped until the arrival of the signal ". If any characters or spaces are repeated in the text line, then in block 8 the code of the repeated character is written, the command is repeated and its number is repeated.

5 reps. The repeat code is cleared by the address-changing control unit 9, the address counter 13 is stopped and the character recorded at this address is repeated a required number of times.

The tab command is used for

output of tabular information, for this command, the promotion of the address counter stops to the nearest tabulation position. Such an asynchronous mode of operation with a variable number of characters per line has become

possible thanks to the construction of the address part. In the proposed structure, by the address counter, another, all the addresses of the characters of the displayed text page are calculated. Any of these addresses may

control signals are placed on the register of 14 lines of the starting address, of the lines and on the register of 15 starting addresses of the page.

Consequently, any rearrangements associated with a change in the number of characters per line, lines in a frame, and their linear dimensions relate only to schemes that provide external clocking of the address part.

The device allows CRT 12 to display both alphanumeric and graphical information. The vyvovoda mode of the graphic information is specified by the code recorded in the RAM block 8. This code is decrypted in block 10 of the decoder and the fixed memory, from which control signals are sent to counters 2 and 3, which define the linear dimensions of a point on the screen. At the same time, in block 8, the memory does not store character codes, whose configurations are sewn up in block 10 of the permanent memory, but their scan codes, the units of which define the light points on the screen, and these codes go to the shift register 11 and are highlighted on screen CRT 12.

The structure of the device is quite flexible and allows you to change the size of characters displayed on the screen, change the number of characters in a line and the number of lines in a frame, smoothly move information on the screen, display as character and graphic information. The latter is especially important since conventional devices displaying symbolic information are not intended for displaying graphs and pictures, and special graphic displays are very expensive.

The addresses of the RAM blocks do not have a hard connection with the position of the displayed characters on the screen, which allows using the address change control block to work with an arbitrary number of characters in a line and lines in a frame, enter information into a block of RAM in compressed form and save memory as the most expensive device node. This saving is especially significant when displaying graphic information, since usually graphic images occupy no more than 10–20% of the screen area. This effect is achieved when hardware costs are reduced, since the character counter with the logic block and the text line counter in the synchronization part of the device are replaced with simple divisors. The starting row address counter, row address counter and divisor are replaced with simpler register devices. A compressed method of recording information can significantly reduce the amount of RAM.

Claims (1)

Invention Formula Device for displaying information on the screen of a cathode ray tube A CRT containing a generator, a point counter, a TV line counter, line and frame scanners, an RAM block, an address counter, a decoder block and a fixed memory, and a shift register, the generator output connected to the first input of the point counter, the first the output of which is connected to the control input of the shift register, the intermediate outputs of the TV line counter are connected to the control inputs the decoder unit and the fixed memory, the information outputs of which are connected to the information inputs of the shift register, the output of which is connected to the electron-beam tube, the outputs of the address counter are connected to the inputs of the main memory unit, and the outputs of the horizontal and frame scanners to the CRT, different from that, in order to simplify the device and expand the area of its application by providing the display of graphic information, changing the characters, their number per line and the number of lines in the frame, it contains line and frame frequencies, the register of the starting address of the lines, the register of the starting address of the pages and the control unit for changing the address, the outputs of the address counter are connected to the inputs of the register of the starting address of pages and to the first inputs of the register of the starting address of lines to the second inputs of which are the outputs of the register of the starting address page 0, the outputs of the register of the starting row address are connected to the inputs of the address counter, the outputs of the RAM block are connected to the address change control block, the control input of which is connected to the second output of the point counter, the information outputs of the address change control block are connected to the information inputs of the decipher block and constant memory, and the control output is connected to the first control input of the address counter, to the second input of which is the output of the horizontal frequency divider, which is also connected to the first input of the television counter lines, with the input of the horizontal scanning signal generator and with the input of a frame frequency divider, the control outputs of the decoder unit and the fixed memory are connected to the second input of the point counter and the second input of the TV line counter, and the output of the frame divider is connected to the input of the frame decoder of the frame scan signal and to the first control input of the register of the initial address of the pages, to the second input of which the control input is connected, and the overflow output of the television line counter - to the control To the input of the register of the starting address of the lines. Sources of information taken into account in the examination 1. US Patent No. 3827041, cl. 340-172.5, 1973 (prototype).