JPH1124623A - Monitor connecting board and monitor connecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a monitor connecting board and a monitor connecting- method in which dot information such as character or pattern can be written into a video memory regardless of text and graphic modes and properly displayed on the monitor of a digital interface connected to the output of a personal computer. SOLUTION: In test mode, it is repeated to retrieve a kanji (Chinese character) ROM 3 at a prescribed time interval to read the dot information of the character of a cord written in a text video memory 4 and writing it in a video memory. In graphic mode, the dot information such as character or pattern displayed by the graphic data read from an input part such as keyboard or a hard disc, and the dot information written in the video memory is outputted as digital signal regardless of test mode and graphic mode.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a monitor connection board that is mounted when a digital interface monitor is connected to a personal computer operating in a text mode and a graphic mode.

[0002]

2. Description of the Related Art A personal computer equipped with Windows (registered trademark of Microsoft Corporation) as an OS generally operates in two modes, a text mode (DOS mode) and a graphic mode (Windows). In the graphic mode, since data corresponding to each dot on the screen is handled, a large amount of data is handled.
For this reason, a method has been adopted in which a graphic accelerator board for performing a screen drawing process is mounted in place of the CPU of the personal computer main body to speed up the drawing (graphic display) in the graphic mode and reduce the load on the CPU. I have.

FIG. 6 shows a personal computer (NEC) equipped with a conventional graphic accelerator board.
FIG. 9 is a diagram showing a configuration of a portion for outputting display data in a PC-98 manufactured by the company. This type of personal computer switches between output of display data in text mode and display data in graphic mode. Reference numeral 31 denotes a CPU of the personal computer. Reference numeral 32 denotes a graph controller that outputs display data in the text mode. Reference numeral 33 denotes a kanji ROM in which dot information is stored for each character. The kanji ROM 33 contains kanji, hiragana,
Dot information is stored for each character such as katakana. 3
Reference numeral 4 denotes a text video memory for writing a character code of a character to be displayed in the text mode. Reference numeral 35 denotes a window accelerator that outputs display data in the graphic mode. 36 is in the graphic mode,
This is a graphic video memory for writing dot information such as characters and figures to be displayed. 37 is a text mode,
A switch for switching display data output in the graphic mode. This switch 37 is controlled by the CPU 31. Reference numeral 38 denotes a connector for outputting display data from the personal computer main body, and a display device 39 is connected to the connector 38.

[0004] In the text mode, the character code of the character to be displayed is written in the text video memory 34.
The graph controller 32 searches the kanji ROM 33, reads out the dot information of the character of the character code written in the text video memory 34, converts it into an analog signal, and outputs it. At this time, the CPU 31
The switch 37 is switched so that the output of the graph controller 32 is input to the display device 39 via the connector 38. On the other hand, in the graphic mode, dot information such as characters and figures to be displayed is written in the graphic video memory 36. Window accelerator 35
Converts the dot information written in the graphic video memory 36 into an analog signal and outputs it. At this time, the switch 37 is switched by the CPU 31 so that the output of the window accelerator 35 is input to the display device 39 via the connector 38. As described above, the graph controller 32 and the window accelerator 35 correspond to the CPU 31 of the personal computer main body.
By performing the screen drawing process instead of, the drawing speed is increased and the load on the CPU 31 is reduced.

Conventionally, a CRT monitor is generally used for the display device 39 of a personal computer. However, recently, a CRT display is large and requires a large space, and power consumption is large. Liquid crystal displays that can be driven with low power consumption and save space in the installation area have begun to be used as display devices. However, the personal computer displays the CRT on the display device 39.
Since it is assumed that a display is used, display data is output as an analog signal. On the other hand, liquid crystal displays are driven by digital signals. Therefore, an A / D converter for converting input display data into a digital signal must be provided in the liquid crystal display, and the input display data must be converted into a digital signal.

However, since a personal computer converts display data from a digital signal to an analog signal and outputs it, and a liquid crystal display converts an analog signal to a digital signal, the display data is changed from "digital" to "analog". → The conversion is repeatedly performed as “digital”. During this conversion process, the display data is degraded, and the characters displayed on the screen are blurred or the picture lacks sharpness. there were.

Therefore, there has been proposed a method in which a digital accelerator board for outputting display data as a digital signal is mounted on a personal computer main body, and a liquid crystal display of a digital interface is connected to an interface of the board. In this method, display can be performed by driving a liquid crystal display with display data of a digital signal output from a personal computer.
Since the conversion from “analog” to “digital” is not performed, there is an effect that display data is not deteriorated and image quality can be improved.

[0008]

However, the digital accelerator board stores the data in a text video memory of a personal computer of the type shown in FIG. 6 (a personal computer that switches output of display data between a text mode and a graphic mode). Because it was not equipped with a function to output dot information of the characters of the code, the liquid crystal display connected to the interface of the digital accelerator board
Display in text mode (text display) could not be performed. Moreover, with personal computers,
Power on and start up, text mode (DOS)
Start up in graphic mode (Windows)
s), the memory check and the like at the time of startup are executed in the text mode. Therefore, an error message when a failure is detected is in the text mode execution stage and is not displayed on the liquid crystal display. . Therefore, there is a problem that the user cannot be notified of the content of the failure that has occurred in the personal computer main body.

It is an object of the present invention to write dot information such as characters and figures to be displayed in a video memory regardless of a text mode and a graphic mode.
It is an object of the present invention to provide a monitor connection board and a monitor connection method capable of performing an appropriate display on a monitor of a digital interface connected to an output unit regardless of which mode the personal computer is running.

[0010]

The invention described in claim 1 operates in a text mode and a graphic mode,
In the text mode, the ROM that stores the dot information for each character as display data is searched, and the dot information of the character of the code written in the text video memory is output as an analog signal. A monitor connection board that is attached when a digital interface monitor is connected to a personal computer that outputs dot information such as characters and figures written in the video memory as analog signals. A video memory for writing figures and the like in dot information, and an output unit for outputting dot information written in the video memory as display data as digital signals regardless of the operation mode, and the text video in the text mode. Write to memory Read dot information of the character of the filled-in and code from the ROM, characterized in that to execute repeatedly a process of writing this into the video memory at predetermined time intervals.

In this configuration, in the text mode, the process of reading dot information of characters of the code stored in the text video memory from the ROM and writing the dot information to the video memory is repeatedly executed at predetermined time intervals. In the memory, dot information of characters to be displayed in the text mode is written at predetermined time intervals.
The output unit outputs the dot information written in the video memory as display data. Therefore, the dot information of the character to be displayed in the text mode is output from the output unit, and the monitor of the digital interface connected to the output unit can perform the display in the text mode.

In the graphic mode, dot information such as characters and figures to be displayed is written in a video memory, and the output section outputs dot information such as characters and figures written in the video memory. Therefore, it is possible to cause the monitor of the digital interface connected to the output unit to perform display in the graphic mode.

That is, whether the personal computer is operating in the text mode or the graphic mode, an appropriate display is performed on the monitor of the digital interface connected to the output unit.
For example, an error message when a failure is detected at the time of startup or the like can be displayed, so that the user can be notified of the content of the error.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows output of display data in a personal computer (PC-98 manufactured by NEC) equipped with a digital accelerator board (a monitor connection board according to the present invention) according to an embodiment of the present invention. It is a figure showing composition of a part. Reference numeral 1 denotes a CPU of the personal computer main body. Reference numeral 2 denotes a graph controller that outputs display data in a text mode. 3 is
This is a kanji ROM in which dot information is stored for each character. The kanji ROM 3 stores dot information for each character such as kanji, hiragana, and katakana. There is also a personal computer having an extended kanji ROM (not shown) in addition to the kanji ROM3. Reference numeral 4 denotes a text video memory in which a character code of a character to be displayed is written in the text mode. Reference numeral 5 denotes a window accelerator that outputs display data in the graphic mode. Reference numeral 6 denotes a graphic video memory in which dot information such as characters and figures to be displayed is written in the graphic mode. 7
Is a switch for switching the display data output between the text mode and the graphic mode. This switch 7
Is controlled by the CPU 1. Reference numeral 8 denotes a connector for outputting display data. The connector 8 can be connected to a display device having an analog interface. CPU 1 described above, graph controller 2, kanji ROM
3, a text video memory 4, a window accelerator 5, a graphic video memory 6, a switch 7, and a connector 8 constitute a personal computer main body, operate as described in the above-described prior art, and have an analog interface connected to the connector 8. In this case, the appropriate display is performed in both the text mode and the graphic mode.

Reference numeral 11 denotes a digital accelerator board according to the embodiment of the present invention, which is connected to a bus of a personal computer. Reference numeral 12 denotes a digital interface liquid crystal display, which is connected to the output unit of the digital accelerator board 11. In this embodiment, the digital accelerator board 11 is merely added to the main body of the personal computer. However, the digital accelerator board 11 may be replaced with the window accelerator 5 (removal of the window accelerator 5) which is a configuration of the main body of the personal computer.

FIG. 2 is a diagram showing a configuration of a digital accelerator board. The digital accelerator board 11 includes a control unit 21, a BIOS-ROM 22 in which driver software is stored, a video memory 23 in which dot information such as characters and graphics to be displayed is written, and dot information written in the video memory 23. And an output unit 24 for outputting a digital signal as a digital signal. The digital accelerator board of this embodiment includes a control unit 21
Outputs dot information such as characters and figures written in the video memory 23 from the output unit 24 as digital signals. Then, the digital signal output from the output unit 24 drives the liquid crystal display 12 to perform display.

Hereinafter, the operation of the digital accelerator board of the present embodiment will be described in detail. FIG. 3 is a flowchart showing a process when the personal computer is started. When the power of the personal computer 1 is turned on, the internal BIOS of the personal computer and the initialization of the graph controller 2 are performed by the system BIOS (n1, n2). At this time, if a display device of an analog interface is connected to the connector 8, the initialization of the display device is also executed. Thereafter, the BIOS-ROM 22 of the digital accelerator board 11 is read (n3), and the processing of the contents read from the BIOS-ROM 22 is executed (n4). Details of the processing in n4 will be described later. When the processing of n4 is completed, the contents of the hard disk are read (n5), and after DOS is started, Windows is started (n6, n7).
The text mode is performed while the processing of n1 to n6 is performed, and when Windows is started in n7, the mode is shifted to the graphic mode. After Windows is started in n7 to enter the graphic mode, the mode can be shifted to the text mode, or the mode can be shifted from the text mode to the graphic mode.

Next, the processing in n4 will be described in detail. Figure 4 shows the BIOS of the digital accelerator board
4 is a flowchart of a process written in a ROM 22. Initialization processing of the digital interface liquid crystal display 12 connected to the output unit 24 is performed (n11). Then, interrupt registration is performed to repeatedly execute a text display process described later at a predetermined time interval (for example, at an interval of 0.1 s) (n12). After the interrupt registration, the text display processing is executed at predetermined time intervals.

FIG. 5 is a flowchart showing a text display process. When the interrupt timing comes (n21), the CPU 1 determines whether the current mode is the text mode or the graphic mode (n22). n22,
If it is determined that the mode is the graphic mode, this process is completed. On the other hand, if it is determined that the mode is the text mode, the dot information (font pattern) of the character of the code written in the text video memory 4 is sequentially read from the kanji ROM 3 (n23), and this is written in the video memory 23. Is completed (n24). That is, in the text mode, the dot information of the character of the code written in the text video memory 4 is written to the video memory 23 at predetermined time intervals. Note that the CPU 1 repeatedly executes the text display process every time an interrupt timing is reached.

In the graphic mode, dot information such as characters and figures to be displayed is written in the video memory 23 based on input data from an input unit such as a keyboard (not shown). The control section 21 outputs the dot information written in the video memory 23 from the output section as digital data as display data regardless of the text mode or the graphic mode. The liquid crystal display 12 of the digital interface connected to the output unit
Driven by the display data output from the output unit 24. As a result, the characters, figures, and the like of the dot information output from the output unit 24 are displayed on the screen of the liquid crystal display 12.

As described above, in the text mode, the dot information of the character of the code written in the text video memory 4 is written in the video memory 23, and in the graphic mode, the dot information of the character or figure to be displayed is stored in the video memory 23. Written. Then, the control unit 21 outputs the dot information written in the video memory 23 irrespective of the text mode and the graphic mode to the output unit 24.
To output a digital signal. For this reason, in the text mode, the characters of the code written in the text memory 4 are displayed on the liquid crystal display 12, and in the graphic mode, the characters and figures written in the video memory 23 as dot information are displayed on the liquid crystal display. 12 is displayed. Therefore, regardless of the state of the personal computer (text mode, graphic mode),
An appropriate display can be displayed on the liquid crystal display 12 of the digital interface.

Further, as described above, the image quality can be improved by using the monitor of the digital interface for the display device. Further, since an A / D converter is not required for a liquid crystal display having a digital interface, it can be manufactured at a lower cost than a liquid crystal display having an analog interface.

In the above embodiment, a liquid crystal display has been described as an example of a display device of a digital interface. However, other display devices such as a plasma display can be used as the digital accelerator board 11 of the above embodiment. Can be applied. Also,
The text display process shown in FIG. 5 is repeatedly executed at predetermined time intervals while the personal computer is running. Display can be performed. The text display processing program is stored in the digital accelerator board 1
1 and is read into the memory of the personal computer when the BIOS-ROM 22 is read at n3.

Further, C of the personal computer main body
The present invention is also applicable to a personal computer (DOS / V machine) in which a PU converts a character code written in a text memory into dot information and writes the dot information in a graphic video memory. In this case, the processing of n12 described above may be prohibited. As a method of prohibiting the processing of n12, the personal computer of this method and the personal computer of the method according to the above-described embodiment differ in the address of the memory of the personal computer main body that reads the contents of the BIOS-ROM in n3. Therefore, the address of the memory from which the content of the BIOS-ROM is read is used to determine which type of personal computer is used.
Otherwise, the processing of n12 may be prohibited. Further, as another method, it is also possible to adopt a configuration in which which type of personal computer is mounted in advance is set by a dip switch or the like.

[0025]

As described above, according to the present invention, regardless of the text mode and the graphic mode,
Appropriate display can be performed on the monitor of the digital interface. Therefore, it is possible to display the details of the error detected when the personal computer is started, and it is possible to notify the user of the details of the error.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an output portion to a display device of a personal computer equipped with a digital accelerator board according to an embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a digital accelerator board according to an embodiment of the present invention.

FIG. 3 is a flowchart showing processing at the time of starting a personal computer.

FIG. 4 is a diagram showing a BIOS of a digital accelerator board.
5 is a flowchart illustrating a process written in a ROM.

FIG. 5 is a flowchart illustrating a text display process.

FIG. 6 is a diagram showing a configuration of an output portion to a display device of a conventional personal computer.

[Explanation of symbols]

 1-CPU 2-Graph controller 3-Kanji ROM 4-Text video memory 5-Window accelerator 6-Graphic video memory 11-Digital accelerator board 12-Liquid crystal display 21-Control unit 22-BIOS-ROM 23-Video memory 24-Output Department

Claims (2)

[Claims] 1. A text mode which operates in a text mode and a graphic mode. In the text mode, dot information of a character of a code written in a text video memory is searched by searching a ROM storing dot information for each character as display data. When a digital interface monitor is connected to a personal computer that outputs dot information such as characters and graphics written in the graphic video memory as display data as analog data in the graphics mode, A monitor connection board to be mounted, wherein a video memory for writing character or figure as display data as dot information and a dot signal written in the video memory as display data regardless of an operation mode are outputted as digital signals. And an output unit. At the same time, in the text mode, the dot information of the character of the code written in the text video memory is stored in the ROM.
A monitor connection board which repeatedly executes a process of reading from the video memory and writing the same into the video memory at predetermined time intervals. 2. A text mode which operates in a text mode and a graphic mode. In the text mode, dot information of a character of a code written in a text video memory is searched by searching a ROM storing dot information for each character as display data. A monitor connection that connects a digital interface monitor to a personal computer that outputs dot information such as characters and graphics written in the graphic video memory as display data in the graphics mode in analog mode. A method comprising: outputting dot information such as characters and graphics written in a video memory as digital data as display data irrespective of an operation mode; and, in a text mode, reading out a code written in the text video memory. Character The Tsu door information the ROM
And a process of writing the data to the video memory repeatedly at predetermined time intervals.