JPS6046734B2 - character display system - Google Patents

Description

Detailed Description of the Invention The present invention transmits character codes and character patterns from a terminal control device (hereinafter abbreviated as TC) to a video data terminal device (hereinafter abbreviated as VDT), and transmits a character code and a character pattern to a plurality of devices controlled by the TC. The present invention relates to a character display system that displays character data sent from a host device on the screen of a VDT display device.

FIG. 1 is a block diagram of the character display system, and FIG. 2 is a flowchart showing its operation.

In Figure 1, 1 is a terminal control device (TC), 2
is the TC code buffer, 3 is the TC code converter,
4 is a TC character generation buffer (hereinafter abbreviated as CG buffer); 5 is a video data terminal device (VDT);
6 is a VDT code buffer, 7 is a VDT code converter, 8 is a VDT (7) CG buffer, 9 is a display control device, 10 is a display device, and 11 is a TC data buffer. First, the operation of a conventional character display system will be explained with reference to FIGS. 1 and 2.

Before the bulleted explanation below. The numbers inside correspond to the numbers in the flowchart of FIG. 1: Data is sent from the higher-level device A (channel device, etc.) to the data buffer 11 of the TCI.

2: Edit this data to the character code for one screen, and
Store the code of I in buffer 2.

3: Transfer this character code from TC code buffer 2 to V
Send to code buffer 6 of DT.

4: Read character code from code buffer 6, VDT
A search is made to see if there is a character code corresponding to the code converter 7.

If so, proceed to step 5. : Set the use flag added to the code of the code converter 7 to ``1''.

6: 4, 5 until all character codes are searched
Repeat.

When the processing is completed, the process proceeds to 7. 7: Read the character code from the code buffer 6 again and search for a corresponding character code in the code converter 7.

If there is a corresponding code, proceed to @; if not, proceed to 8.
8: If there is no code in the code converter 7, select the character code from DT5 to TCl and request the character pattern.

9: TCl searches for a character pattern corresponding to the character code using TC's code converter 3, and converts it to TC's CG.
Read from buffer 4 and send to VDT5.

[Phase]: When the VDT 5 receives a character pattern, it sequentially searches and detects locations where the flag used by the code converter 7 is "0" starting from the smallest address.

◎: When the location is detected, the code and the storage address of the DT(7) CG buffer 8 are stored in the code converter 7, and the use flag is set to "1".

Also, the character pattern is stored in the CG buffer 8. @: The character pattern read from the CG buffer 8 according to the address of the code converter 7 is displayed on the screen of the display device 10 via the display control device 9.

◎: Repeat steps 7 to @ until display of character patterns for all character codes is completed.

In the conventional character display system described below, nothing is stored in the code converter 7 and CG buffer 8 of the VDT 5 when the power is turned on. Therefore, for a while after processing starts, there will be many cases where there is no code in the process 4 above, so character pattern requests in the process 8 will increase, and the number of accesses to the TCl that controls multiple DT5s will increase, causing the system to Overall processing power decreases. Furthermore, when searching for a location with the usage flag ゜゛0゛ in the process of [phase], the search starts from the smallest address. Therefore, although it is a character code that is used frequently from the perspective of overall processing, it happens to be unused on the screen being processed, so it is often replaced with other character codes that are used less frequently from a general perspective. , which leads to a decrease in the processing capacity of the entire system. In addition, the characters displayed on one screen are rarely different for all types, and usually the code converter 7
The utilization rate of old addresses is low. The present invention aims to reduce the overall processing capacity of the conventional character display system as described above, that is, the reduction in processing capacity due to frequent requests for character patterns, and the useless processing due to replacement of frequently used character codes. , the problem of low utilization rate of the code converter 7 at an old address, and therefore of the converter as a whole, and the like, and to provide a character display system that is efficient as a whole and has a high processing capacity.

In order to achieve the above object, the present invention selects character codes from VDT to
Select a number equal to the capacity of the code converter in the DT, and place these character codes in such a way that the relatively infrequently used ones are placed at the lower addresses of the DT code converter, and the relatively more frequently used ones are placed at the older addresses. ). For example, select the capacity n of the DT code converter and arrange the frequently used character codes, with the less frequently used character codes at the front and the more frequently used character codes at the rear, and perform data processing on the TC. The character code group can be stored in the code converter 7 as described above by storing the character code in the code buffer 2 of the TC and performing the processing in steps 3 to @. However, during this time, the display control device 9 prevents the character pattern from being displayed on the display device 10 so that the operator is not aware of it. FIG. 3a is a diagram showing a state in which the n frequently used character codes are arranged in the code buffer in order from left to right, from least frequently used to most frequently used. Here, n is a number indicating the capacity of the code converter 7 of the VDT. FIG. 3b is a diagram showing the state inside the code converter 7 after the processes 3 to 3 in the flowchart have been completed. Less frequently used items are on top, and more frequently used items are on the bottom. What is the address? CG buffer 8
This is the address of the character pattern corresponding to the relevant character code within. Today, small high-speed storage elements of about 4kb using semiconductors, rewritable fixed storage devices, etc. are easily available, so in the above manner, frequently used character codes and their addresses can be input to the code converter 7. CG at the same time
It is easy to add means for storing the respective character patterns in the buffer 8. Code converter 7, C
If frequently used character codes and character patterns are stored in the G buffer 8, even if the characters on the screen during information processing include frequently used kanji, in most cases the code converter 7 This means that the content can be processed as is, eliminating the large loss of time associated with requesting character patterns.

Even if the most frequently used character code is located at the old address of the code converter 7, the capacity of the code converter 7 is relatively small and if a high-speed element is used, the difference in access time depending on the age of the address will be short. This is not a problem if compared to the time it takes to read out a character pattern from the TC or an external storage device as a character pattern request. If the most frequently used character code is placed in the lower address of the code converter,
If the character code is replaced with a character code that is used very infrequently for a unique screen, the character pattern must be requested again for the subsequent normal screen display, resulting in a large loss of time. On the other hand, according to the present invention, if a character code that is extremely frequently used is stored at an old address of the code converter 7, a request for a special character pattern will be issued for one screen by chance, and in response to this request, When searching for the storage location of the character code corresponding to the given character code, even if the character code that is extremely frequently used is unused,
The probability of being replaced is extremely low. Therefore, special characters for each screen are stored in the lower addresses of the code converter 7 and are often replaced, but extremely frequently used characters that are commonly used in many screen displays are stored in the lower addresses of the code converter 7. Since they are stored in addresses and are rarely replaced, the useless and frequent loss of time caused by replacing extremely frequently used characters can be avoided, and the throughput of the system can be improved. The means for storing frequently used character codes in the VDT code converter 7 as described above is first activated when the power is turned on.
Since nothing is stored in the G buffer 8, character patterns may be requested from multiple DTs at the same time at the start of processing.
It is possible to avoid a decrease in the processing capacity of the entire system due to flooding of C.

Also, even if you store frequently used character codes in the code converter 7 of the VDT, with those that are used relatively infrequently in the lower addresses and those that are more frequently used in the older addresses, it will take a while. Because it is being processed continuously and sometimes even extremely frequently used characters are replaced,
Gradually, the contents stored in the code converter 7 change in a direction that is unfavorable in terms of processing efficiency. To solve this problem, a means for storing frequently used character codes in the code converter 7 is activated every time the continuous processing time of the character display system elapses at a predetermined period. All you have to do is refresh the content. While the character code storage means according to the present invention is in operation, the original display processing is temporarily stopped, but the processing capacity is improved over a long period of time. As explained above, according to the present invention, by using relatively few additional means,
This has the effect of providing a character display system with improved processing capacity for the entire system and over a long period of time.

It is clear that the present invention is applicable not only to character display systems but also to other input/output systems that perform similar functions and processing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a character display system, FIG. 2 is a flowchart showing the operation of the character display system, and FIG. 3 is an explanatory diagram of character code arrangement according to the present invention in a code converter. 1...Terminal control device (TC), 5...
...Video data terminal equipment (VDT), 6
...■DT code buffer, 7...V
DT code converter, 8... VDT character generation buffer (VDT CG buffer), 10...
Display device.

Claims (1)

[Claims] 1. A code buffer that holds character codes for one screen to be displayed on a display device, and a code converter that stores a character pattern corresponding to the character code read from the code buffer. From a plurality of video data terminal devices, each equipped with a character generation buffer that holds one screen worth of character patterns to be displayed on a display device, and a terminal control device that controls the plurality of video data terminal devices. In a character display system, the number of frequently used character codes equal to the capacity of the code converter of the video data terminal device is selected, and these character codes are used at relatively small addresses of the code converter. A character display system characterized by providing means for storing infrequently used characters so that relatively frequently used characters are arranged at older addresses. 2. When the power is turned on and for the specified continuous processing time thereafter,
The character display system according to claim 1, wherein the character code storage means is activated.