JPH0427570B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention provides a screen recovery method, especially when an operator of a display terminal (hereinafter referred to as CRT) accidentally presses the clear key or power key. Regarding the screen recovery method when the screen that was showing up until that time is broken.

(Prior art) Conventionally, this type of screen recovery involves immediately transferring control from the system program to the user application program (hereinafter referred to as the user program).
This is executed by the user program gathering the data necessary for screen recovery and then requesting the system program to send the screen data again.

In other words, after the user program requests the system program to send screen data to the CRT by executing the SEND command,
The RECEIVE command causes the system program to wait for a response. On the other hand, when a transmission request is received from the system program, the screen format data consisting of the screen format displayed on the CRT (for example, the frame of a slip) and the definition parameters of each field is synthesized with user data (for example, table headings). Create screen data using
Send to CRT.

Based on this screen data, the CRT operator inputs data on the displayed screen using the keys, and after completing the key-in of data for one page.
When the WRITE key is pressed, the system program passes the key-in data to the user program that formed and edited the key-in data, if the key-in is normal. The user program stores the input key-in data in the main memory for each CRT, moves to the next command step, and when it encounters the SEND command again, executes the SEND command for the next screen data.

By the way, if the operator accidentally breaks the screen, the system program will not be able to properly edit the format and will notify the user program of this fact.
In response to this, the user program attempts to restore the screen by collecting the data necessary for restoring the screen and executing the SEND command again.

In addition to the above-mentioned screen format data and user data, the data required at this time is often considered to be key-in data for the previous screen or data in a general database.

(Problems to be Solved by the Invention) In such a conventional system, the user program becomes complicated due to the built-in response to the screen being broken, and when the screen is broken, the system program and the user program are Since the control authority is transferred back and forth between the two, there are problems in that the number of exchanges between the two increases, the response time for screen restoration becomes longer, and the main memory capacity for storing key-in data increases.

Therefore, an object of the present invention is to provide a screen recovery method that solves the above problems by eliminating the need for user program intervention for screen recovery.

(Means for solving the problem) To this end, the method of the present invention adds control information to the screen data sent to the CRT in response to a transmission request from the user program, if specified in advance. If an operator breaks the screen displayed on the CRT, the screen data written to the disk device will be written out in response to a predetermined key press on the CRT. It is characterized in that the destroyed screen data is displayed again without intervention from the user program by reading out the data based on the control information and transmitting it to the CRT.

(Embodiment) FIG. 1 is a processing flow showing an embodiment of the present invention, and FIG. 2 is a hardware configuration diagram of the embodiment.

First, referring to FIG. 2, this embodiment is composed of a central processing unit 1, a main storage device 2, two magnetic disk devices 3 and 4, and four CRTs 5, 6, 7, and 8. ing. The main storage device 2 has a system program configured as shown in Figure 1.
It has an area for storing various data including SP and a user program UP consisting of screen format data FD, user data UD, etc.

The magnetic disk device 3 stores a large amount of screen format data FD in advance, and these screen format data FD are read into the main storage device 2 in response to a call from the central processing unit 1. Further, the magnetic disk device 4 is used to store screen data to be saved together with control information.

Each of the CRTs 5, 6, 7, and 8 displays screen data in accordance with instructions from the central processing unit 1, and allows data to be input by an operator using a keyboard. It is also possible to display the same screen data on multiple CRTs at the same time.

Next, the operation of this embodiment will be explained along the processing flow shown in FIG.

When the central processing unit 1 is executing the user program UP and reaches an instruction step where the SEND command is set, control of the program is transferred to the system program SP, and the screen name attached to the SEND command is is notified to the system program SP.

The system program SP reads the screen format data FD corresponding to this screen name from the magnetic disk device 3 to the main storage device 2, synthesizes it with the user program UD that reflects the processing results of the user program UP, and creates a screen. Create data (steps in Figure 1). The screen data that is the result of this synthesis is written to the magnetic disk device 4 and then sent to the destination CRT (step) when there is a save specification by JCL as described above.
The screen will be displayed.

The operator performs the key-in operation while looking at this screen, and when the key-in for one screen is successfully completed, presses the WRITE key on the keyboard. In response to this, the system program SP performs format editing processing on one screen of key-in data of the key-in input agent (step), and then transfers it to the user program UP together with the control authority.

The user program UP is the previously executed SEND
After the command, the RECEIVE command was used to wait for a response from the system program SP side.
When control is transferred from the system program SP, the key-in data is taken over and the next instruction step is executed. Then, when the command step in which the SEND command is set again is reached, the above-described processing is repeated for the next screen.

The above process is performed when the key-in operation by the operator is completed normally, but the operator may accidentally press the clear key or power key and damage the screen. In such a case, press the recovery key on the keyboard to restart the system program.
The flow of SP moves from step to step,
The screen data is read from the magnetic disk device 4 and transmitted to the CRT. The operator then restarts the key-in operation from the beginning while looking at this easily restored screen.

(Effects of the Invention) According to the present invention, as described above, by eliminating the need for user program intervention for screen recovery, it is possible to eliminate the complexity of the user program and facilitate screen recovery. In addition, by eliminating the need to store key-in data, the capacity of the main storage device can be reduced.

[Brief explanation of drawings]

1 and 2 show one embodiment of the invention. 1...Central processing unit, 2...Main storage device, 3,
4...Magnetic disk device, 5, 6, 7, 8...Disk play end device (CRT), SP...System program, UP...User program, FD...
...Screen format data, UD...User data.

Claims (1)

[Claims] 1. If specified in advance, screen data sent to a display device in response to a transmission request from a user program is written to a specified disk device with control information added thereto. , When the end operator breaks the screen displayed on the display end device, the screen data written on the disk device is converted into the control information in response to pressing a predetermined key on the display end device. 1. A screen recovery method, characterized in that the corrupted screen data is displayed again without the intervention of the user program by transmitting the corrupted screen data to the display end device that has been read out based on the above information.