JPS58107583A - Display unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to display attribute control of a display screen in a display device.

(Background Art) A conventional display device is shown in FIG. 1, and the operation in FIG. 1 will be briefly described. First, by specifying an address from the synchronization circuit 4, the screen memory 1 stores codes for characters and symbols to be displayed, and FA (Field Attribute) codes that give display attributes on a field-by-field basis to characters, Φ symbols, etc. Sequential display characters Φ symbol etc. and FA
The code is read. Keo FA code is FA code and F
This gives display attributes to the field between the A code, and as shown in Figure 2, when b8=, o, it is a character/symbol code, when b8=1, it is an FA code, and each bit of bo-b. can define display attributes such as scrolling, blinking, non-display, high brightness, and ruled lines. Now, the code read from the screen memory is the pattern memory 2a and the video generator 2.
The video data is outputted to a pattern generator 2 consisting of a code and converted into video data according to the code. For this video data, F
A display attribute control circuit 3 consisting of a video control section 3a that controls display attributes according to the specification of an A code and an AND circuit 3b that gates a display area signal output from a synchronization circuit can perform inversion, blinking, non-display, high brightness, ruled lines, etc. In the above method, display attributes are added and the display is performed on one display section 5. As shown in FIG. They are arranged continuously according to the display capacity. In other words, if the number of displayed characters is N characters horizontally and M lines vertically, the screen memory has N characters horizontally and M lines vertically.
If the screen display in FIG. 4(a) is moved forward by one line while the rows are held, the screen display in FIG. 4(b) becomes the FA shown in FIG. 4(a).

Since the characters C, D, and H do not exist in the screen memory, no display attributes are added to the characters C, D, and H displayed on the screen in FIG. 3(b), and they are displayed with initial values unique to the device.

In this way, when display attributes specified between FA codes are specified over multiple lines, if you move up or down one line, the FA code will not exist between screen memories and the display attributes will not be added. there were.

(Problems to be solved by the invention) In order to eliminate these drawbacks, it is an object of the present invention to provide a display device in which the FA designation is valid at the first character position of each line number even when moving a line down, and its characteristics are as follows. ,
A screen memory (1) that stores the character fist symbol code to be displayed on the screen (5) and the FA code that gives display attributes to the code in field units, and the codes sequentially read from the memory ('1) into pattern data. a pattern generator (2) to be converted; and a display attribute control circuit (2) that modifies the pattern data obtained from the pattern generator (2) with the FA code and displays it on the screen (5).
3), the display device having the screen memory (1);
) has an area for each line that stores an FA code for adding display attributes after the first letter of each displayed line, and the pattern data is modified according to the characters in the area, and the area is The characters themselves are located on a display device equipped with a display attribute control circuit (6) for not displaying them on the screen (5).

(Structure and operation of the invention) FIG. 5 is a diagram showing the principle of display attribute control related to the present invention,
Depending on the correspondence between the display screen and screen memory, if the number of displayed characters is N characters horizontally and M lines vertically, the screen memory will be N characters horizontally and M vertically.
0/1.0/2.0/3... that spans each line.
Store the FA code in O/M and hide this area. In this case, if the display screen corresponding to FIG. 4 is shown in FIG. 6, if the 0 line screen that becomes the display screen in FIG. The screen becomes Figure 4 (
The disadvantage of not adding display attributes to characters c, D, and Em as shown in b) can be eliminated. In other words, display attributes can always be given after the first character. Now, FIG. 7 is a block diagram showing one embodiment of a display device according to the present invention.

Note that the same reference numerals are used for the constituent elements used in reference numerals 1 to 5. In FIG. 7, 6 is a display area control section for controlling the display area.

Next, the display operation of the display device using the L-styl acid will be explained. First, codes sequentially read out from the screen memory 1 by addressing from the synchronization circuit 4 are converted into video data via the pattern generator 2, and a display attribute is added to the video data by the display attribute control circuit 3. 0/1.0/2.0/3...O of screen memory 1 shown in FIG.
The FA code stored in /H is read out, the display attribute specified by the FA code in the display attribute control circuit 3 is added by the video control unit 4a, and the display area control circuit 6 displays one character of this FA code. The output of the display area control signal generated by the AND circuit 4b is gated to make it non-display, and each ! A display attribute is always given after the first letter of te, and it is possible to display N characters horizontally and M lines vertically. Note that the display area control circuit 6 operates according to the block diagram shown in FIG. The flip-flop l is output from the synchronous circuit, and the AND circuit 2 gates the signal delayed by one character display time and the display area control signal output from the synchronous circuit, and gates the signal 071,0/2.0/of the screen memory. 3...
- The FA code area stored in 0-/N is removed from the display area control signal and output to the AND circuit 3b.

As explained above, according to the display device according to the present invention, an area for storing an FA code that adds a display attribute after each bullet is placed in the screen memory immediately before each display bullet code, and the contents of this area are By displaying, display attributes can be added after each bullet, and display attributes can always be added even if the display screen is divided into upper and lower halves and a line-up/line-down display is performed for each. As for the hardware, the normal display screen is 80 characters horizontally and 25 lines vertically, for a total of 2000 characters.
The screen memory is required for 2000 characters and 25 characters for the bullet character display attribute of each line, resulting in a total of 2025 characters, but the screen memory is limited to 20 characters due to the memory chip limit.
Since it is normal to have 48 characters, normally only the display area control circuit that hides the FA code area for the bullet character display attribute of each line without increasing the screen memory is added to Figure 1. This can be achieved with

(Effects of the Invention) The present invention assigns the FA code indicating the display attribute to the first address of each line on the display and hides it, so the display attribute can be maintained even if the display screen is moved up or down by one line. can.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing a conventional display device, Fig. 2 is an illustrative diagram showing the relationship between characters, symbols, etc. in the screen memory in Fig. 1 and display attributes, and Fig. 3 is a screen diagram showing the screen in Fig. 1. An explanatory diagram showing the relationship between the memory and the display screen; FIGS. 4(a) and (b) are explanatory diagrams showing the increment of one line on the display screen in FIG. 1; FIG. 5 shows an embodiment of the present invention. Principle diagram showing the relationship between screen memory and display screen, FIGS. 6(a) and (b)
is an explanatory diagram showing moving up one line of the display screen in FIG. 5,
FIG. 7 is a block diagram showing an embodiment of the present invention, and FIG. 8 is a block diagram showing a display area control section in FIG. 1; Drawing memory, 2; Pattern generator, 3; Display attribute control circuit, 4; Synchronization circuit, 5; Screen,
6; Display area control circuit. Patent applicant Oki Electric Industry Co., Ltd.

Claims (1)

[Claims] and FA that gives display attributes to the code in field units.
A screen memory (1) that stores the code, and a screen memory (1) that stores the code.
) to the code to be read next as pattern data &! a pattern generator (2) for converting and the pattern generator (2)
In the display device, the screen memory (1) includes a display attribute control circuit (3) that modifies pattern data obtained from the FA code with the FA code and displays it on the screen (5). Each line has an area for storing ``FA code'' for one character, and the pattern data is modified according to the characters in the area, and the characters in the area themselves are not displayed on the screen (5). □ A display device characterized by being equipped with a display area control circuit (6).