JPS59106B2 - CRT display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a CRT (cathode ray tube) display device that displays characters, numbers, figures, etc., and in particular, when there is data that you want to leave on the screen without erasing it, you can protect it and effectively line it up. This relates to a CRT display device that can be uploaded.

In general, CRT display devices are widely used for monitoring the output of computers and the like and for consoles.

This is largely due to the fact that CRT display devices are relatively inexpensive compared to the number of characters they display, and are fast and noiseless. However, with this CRT display device, the number of characters that can be displayed is determined by the size of the cathode ray tube, and it is not possible to display any number of characters.

On the other hand, a typewriter fulfills its function by printing data on paper, so it has the advantage that the data remains as a record and there is no limit to the number of characters. The present invention is based on CR
The T display device was also intended to have functions similar to those of this typewriter. Generally, a CRT display device operates in a normal mode and a typewriter mode (line-up mode), and the modes are changed by a switch or a command from a computer.

When the CRT display device is switched from the normal mode to the typewriter mode, the cursor moves to the top position of the bottom line as shown in FIG.

The next data to be transferred is displayed at the cursor position, and is sequentially moved to the right one position at a time. The data transferred in this way is displayed one after another on the CRT screen, but if the number of characters exceeds one line, or if there is a CR (carriage return) code or NL (new line) code in the transferred data. CRT if
The display data on the screen is lined up line by line as shown in FIGS. 2A and 2B, and the display data on the top line disappears one by one. By providing the line-up function as described above, new information can be displayed one after another on the CRT.

In this case, among the data that is lined up and disappears, there is also information that should be preserved. However, conventional CRTs
Since the display device performs line up for the entire screen, it has the disadvantage that necessary information that should be kept is also lined up and disappears. The present invention has been made in view of these drawbacks, and provides a CRT display device that has a function of protecting each line and allows the display contents of a desired line to remain on the screen as desired. It is something.

The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 3 shows one embodiment of the present invention, in which 1 is a character memory that stores data to be displayed as a code signal and has a storage capacity of at least one screen; The memory 1 has a flow section memory 2 for storing whether or not each row is protected, and the memory 2 is added for each row. The character memory 1 is addressed by row and column address registers in synchronization with the scanning of the CRT 2O, and data is sequentially read from the memory 1 and supplied to the character generator 13.
Here, the code signal is converted into a dot signal for display on a CRT. The signal converted in this way is serial
The signals are supplied to the parallel conversion circuit 14, subjected to serial/parallel conversion, and then sequentially displayed on the CRT 2O. When displaying data, the same row is read out repeatedly for the number of vertical dots of pixels. Also, when reading or writing data to the character memory 1, the data is addressed by the row and column address circuits, and the data is read or written via the buffer memory 12, which has a storage capacity for one row. The information in the flow section memory 2 of the character memory 1 is
When addressed, it is read out to the flow section detection circuit 11, and if a flow section is detected, it outputs ゜"1゛゜, otherwise it outputs "゜0゛.

7 is a column address register, character memory 1
Used when reading or writing data to.

The count is sequentially counted up based on the output of the AND gate 21, and addressing for one row is performed. Reference numeral 3 designates an address counter which is counted up in synchronization with the scanning of the CRT 2O when displaying the data in the character memory 1.

Reference numeral 5 denotes a switching circuit that switches the output of the column address register 7 or the column address counter 3 to read, write, or display data in accordance with a signal d from the control unit 25;
It is supplied to the character memory 1 as a column address signal.

Reference numeral 8 denotes a row source address register for addressing the row before line-up when line-up is performed, and the second row from the top of one screen is initially addressed by the signal a output in the initial state.

Furthermore, when the AND gate 15 is opened, the source address register 8 is counted up by one, and the next row is addressed. Reference numeral 9 denotes a destination register for addressing the next row to be transferred at the time of line up, and addresses the first row of one screen by the signal a output in the initial state.

When the AND gate 18 is opened, the destination register 9 is incremented by 1 and the next row is addressed. Reference numeral 10 denotes a switching circuit that switches the outputs of the source address register 8 and destination register 9 in response to a signal b from the control section 25.

A row address counter 4 is used to address the character memory 1 during display, and operates to count up one row after the column address counter 3 displays the number of dots. Reference numeral 6 denotes a switching circuit that switches between the switching circuit 10 and the address counter 4 in response to a signal d from the control section 25.

Next, according to the flowchart of the control section shown in FIG.
The operation of the illustrated embodiment will be described in detail.

However, the lines currently displayed on the screen are A,
The following description will be made assuming that only line B is protected. In the initial state, the destination register 9 addresses the first row A by the signal a from the control unit 25.
Source register 8 addresses the next B row. Here, the control section 25 first controls destination protection detection (shown in FIG. 4, 50), and at this time, the address signal of the destination register 9 is selected by the signal b from the control section 25. Furthermore, since the switching circuit 6 is in the process of reading and writing data at this time, the address signal of the switching circuit 10 is made valid by the signal d, and the address signal is supplied to the character memory 1. At this time, the information in the flow section memory 2 is read out to the flow section detection circuit 11, and since the A row is not protected here, the detection circuit 11 outputs "0". Next, the control unit 25 detects the source flow section (the fourth
(shown in FIG. 51). At this time, the switching circuit 10
is switched to the source register 8 side by the signal b, the source register 8 addresses the B row of the character memory 1, information “B” of the flow section memory 2 is read out, and the flow section detection circuit 11 supplied to Here, since row B is protected, two signals are output from the control section 25. On the other hand, the flow section detection circuit 11 outputs "1" and inputs it to the AND gate 23. At this time, since the 2 signal is output from the OR gate 22, the AND gate 23 opens and the OR gate 19
The signal is input to the AND gate 15 via the gate 15, and the source register 8 increases by one count (as shown in FIG. 4, 63). Source register 8 therefore addresses the next C row. As the source register 8 counts up by 1, the conditional flip-flop is set (as shown in FIG. 4, 64), and then the source flow section is detected again (see FIG. 4, 5).
1).

As a result, the flow section detection of the C row is performed, and since the C row is not protected here, the data C1 of the C row addressed by the source register 8 is read out (
4) is stored in the buffer memory 12. Subsequently, the data C1 of the buffer memory I river 2 is stored in the position a1 of the A row addressed by the destination register 9 (as shown in FIG. 4, 53). Subsequently, the column address register 7 is counted up (as shown in FIG. 4, 54).

That is, at this time, the AND gate 21 is opened by the output of the 6 signals from the control section 25, and the column address register 7 is counted up by one. Here, it is detected whether or not the line has ended (as shown in FIG. 4, 55). If it has not finished, the information in line C is read out again by the source register 8 (
52), data C2 is read into the buffer memory 12 by the source register 8 and column address register 7, and data C2 stored in the buffer memory 12 by the destination register 9 and column address register 7.
is stored in the A2 position of the A row. Thereafter, the column address register 7 is counted up (as shown in FIG. 4, 55).
In this way, the data in row C is moved or lined up to row A, and when the end of the column is reached, the process proceeds to FIG. 4, 56. At this time, since the conditional flip-flop is set, the process advances to FIG. 4, 59, and three signals are output from the control section 25. At this time, the information in the source register 8 is transferred to the destination register 9 via the AND gate 17 (as shown at 59 in FIG. 4). Therefore, the destination register 9 becomes the address of the C row. Subsequently, the source address register 8 is counted up by outputting a 4 signal (as shown at 60 in FIG. 4) to address the next D row. At this time, the conditional flip-flop is reset (as shown in FIG. 4, 61), and the end of the line-up of the character memory 1 for one screen is detected (
(shown in FIG. 458). This line-up detection ends when the source register 8 returns from the lowest row to the first row. If this is not completed, the destination register 9 is used again to detect the protection of the C line (as shown in FIG. 4, 56). The data in the D row is moved to the C row by executing the operations .about.55. In this way, the operation proceeds to the operation shown in FIG. 456, and since it is not A-1 at this time, the control section 25 outputs the 5 signal. Therefore, and gate 15
, 18 are opened, which causes source register 8 and destination register 9 to be addressed to the next row,
Returning to the operation shown in FIG. 458. After character memory 1 is lined up in this way, signal d is supplied from control section 25 to switching circuits 5 and 6, and column address counter 3,
The row address counter 4 is switched and the lineup is displayed on the CRT2O.

Also, new data can be stored and displayed in the lowest row via the buffer memory 12. According to the CRT display device of the present invention, as described above, the character memory 1 for storing character information has a protect memory 2 for each row.
is added to provide a protection function, and when performing line up, it is detected whether or not there is protection, and if there is protection, the line is skipped over that line and the line up is performed, so the data that you want to leave on the display screen. Even if there is such data, it is possible to effectively line up the necessary data without erasing it from the display screen.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams for explaining the operation of a general CRT display device, FIG. 3 is a program diagram of one embodiment of the present invention, and FIG. 4 is a control unit in the same embodiment. This is a flowchart showing the operation. 1...Character memory, 2...Protect memory, 3...Column address counter, 4
・・・・・・Row address counter, 5, 6, 10...
...Switching circuit, 7...Column address register,
8... Source address register, 9...
- Destination register, 11... Flow section detection circuit, 12... Buffer memory, 13... Character generator, 14.
...Parallel/serial converter, 20...
・CRT, 25...Control unit.

Claims (1)

[Claims] 1. Scan the character storage means that stores character information, read out the information sequentially, convert it into a dot pattern by a character generator, display it on a CRT, and move the display data on the CRT upward (or downward). In a CRT display device having a typewriter mode (lineup function) in which line-up operation is performed sequentially, the character storage means has a capacity to store character information for at least one screen, and the information stored in the storage means has a capacity to store character information for at least one screen. a protect storage means for holding information as to whether or not a line is to be protected in relation to and corresponding to a display line displayed on a CRT; a determination means for determining a protect line from read information of the protect storage means; and a character storage. The typewriter mode is equipped with means for transferring the information stored in the means to one line higher (or lower), and means for skipping the protected line when transferring by the transfer means, and At times, prior to the transfer control of information stored in the character storage means, information in the protect storage means corresponding to the line to be controlled is determined, and when the line is a protected line, the transfer control is prohibited, and when the line is not a protected line, the transfer control is prohibited. A CRT display device characterized in that the protection line is skipped and transferred to a higher (or lower) level in sequence, and the display of the protect line remains on the CRT in the typewriter mode.