JPS60140383A - Output control for 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 ('a) Technical Field of the Invention The present invention relates to an output control method for a display device that displays display information such as characters, and particularly relates to a method for controlling the output of a display device that displays display information such as characters, and in particular, it relates to a method for controlling the output of a display device that displays display information such as characters. This invention relates to an improvement in an output control method used when transmitting display information of the display device to another display device in an attached system. (b) Background of the Technology In general, a CRT display device as a display device is ,
Display information such as characters is displayed on a cathode ray tube as a display section, but sometimes there is a demand to print the display information displayed on the cathode ray tube onto recording paper or the like. For this reason, other features are added to the above CRT display device.
Systems equipped with a printer as a device have already been provided. I have this type of J3, and the printer prints 'a'
Since the display speed of llf is much slower than the display speed of a CRT display device, the control section of a ct4'r display device cannot be used as it is as a control section of a printer.

For this reason, a printer control section corresponding to the display control section of a CRT display device is generally provided separately on the printer side, but in this type, the display control section is
For example, a character generator that generates a character pattern as display information, a character code that creates a character pattern for this character generator, and a refresh memory that stores the character code that creates the character pattern and the timing for outputting the character pattern from the character generator. Since the printer is equipped with a CRT controller for controlling the printer, the structure of the printer control section inevitably becomes complicated, and the cost of the entire system increases accordingly. Therefore, in order to solve such problems,
There is a growing demand for the display control section to serve as the majority of the printer control section.

(C) Prior art and its problems Conventional output control methods that meet the above-mentioned demands include, for example, controlling the vertical scanning signal of the horizontal scanning signal on the cathode ray tube during the period when the CRTR display device is not performing display operation. Some printers operate the display control section as a printer control section during the retrace period. This can be done, for example, by creating an interrupt signal indicating the vertical retrace period in the CRTR controller, and causing this interrupt signal to interrupt the microprocessor (hereinafter referred to as MPU).
The character generator outputs printer control information from the printer control information, outputs a character pattern from the character generator based on this printer control information, and sends the character pattern to the printer.

However, in such conventional output control methods, the output to the printer is controlled by software using the MPU, so the speed at which character patterns are transferred to the printer is relatively slow and depends on the printer model. Depending on the
This results in a situation where the transfer speed is insufficient.

As a means to solve this situation, a counter circuit that sequentially outputs the printer control information is installed in the new 1=, and the output from this counter circuit and the refresh memory is sent to the character generator via a multiplexer. It is conceivable that a hardware device could be used in which the character pattern from the character generator is input and transferred between the CRT and the printer, but this type requires a new counter circuit and multiplexer. As a result, the display control section itself becomes more complicated, leading to the problem that the cost of the entire system increases.

(d) Purpose of the Invention The present invention has been made from the above point of view, and its purpose is to An object of the present invention is to provide a method for controlling the output of a 1C display device by making it possible to reliably transfer display information of the display device.

(+3> Structure of the Invention The basic structure of the present invention is that the display control means of the commonly used OR controller synchronizes the address signal corresponding to the number of display information on the display section with the horizontal scanning signal of the display section. The present invention focuses on the fact that the display information of the display device has the characteristic of outputting an address signal consecutive to the address signal of each horizontal scanning period at the same period during each horizontal retrace line 11. display for causing the display information generating means to output display information to be transferred to another output device during the horizontal retrace period immediately before the vertical retrace period of the display device when transmitting the display information to another output device. Control information is stored in a memory in advance, and display information is output from the display information generating means according to the display control information. After the display information is temporarily stored in the buffer memory, it is output to the other output device during the vertical retrace period. It was designed to be transferred.

(f) Embodiments of the Invention The present invention will now be described in detail based on embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing the overall system of a CRTR display device for implementing the output control method according to the present invention.

In the figure, in J3, 1 is a cathode ray tube that serves as the display section of the CRTR display device, 2 is an MPU that controls the entire system of the CRT display device, 3 is a program memory that stores the execution program of the above MPLJ2, and 4 is a CRT.
This is the display control unit of the f-isplay HfM, and this is the
A CRT controller 5 consisting of an LSI connected to LJ2 by a system bus and outputting a predetermined address signal;
A refresh memory 6 that is connected to the MPU 2 by a system bus and that enables character codes as display control information to be rewritten to addresses corresponding to the above address signals, and outputs character patterns as display information based on the above character codes. A character generator 7 consisting of a single-read memory (hereinafter referred to as ROM) or the like; a parallel-to-serial converter 8 for converting a character pattern of parallel dot strings outputted from the character generator 7 into a character pattern of a serial dot string; Parallel-serial converter 8
The video control circuit 9 matches the character pattern output from the video tube 1 with the horizontal scanning speed of the cathode ray tube 1, and outputs a character pattern J5 onto the cathode ray tube 1 during the horizontal scanning period.

In this embodiment, for example, as shown in FIG. Address signals corresponding to display addresses O to 639 on the cathode ray tube 1, that is, addresses O to 639, are converted into horizontal scanning signals (for example, 12 rasters per line of the cathode ray tube 1).
It is configured to output in synchronization with the raster scan signal). The CRT controller 5 also controls, during each horizontal retrace period (thf) of the horizontal scanning signal, a horizontal scanning period during which horizontal scanning is actually performed, in other words a horizontal display period (thf) during which horizontal display characters are displayed. ) is configured to output, for example, 24 consecutive address signals in the same cycle.

Therefore, address signals from address O to address 63 are output to the first character display line of the cathode ray tube 1, and address signals from address 40 to address 103 are output to the next character display line. Similarly below,
Inscribed on the last character display line, address signals from address 600 to address 663 are output.

During the vertical blanking period (tvf) of the horizontal scanning signal, the CRT controller 5 continues to output the address 640. In FIG. 2, the vertical display period (tv) indicates a period during which vertical display characters are displayed.

In this embodiment, 10 is a printer, 11 is a printer control unit, and specifically, a parallel-to-serial converter 12 connected to the MPU 2 by a system bus, and an output from this parallel-to-serial converter 12. a printer control circuit 13 that matches the printing speed of the printer 10 and sets its printing area;
It is made up of. Reference numeral 14 denotes a buffer memory provided between the output end of the character generator 7 and the system bus of MPtJ2.

Next, the operation of the CR display device according to this embodiment will be explained.

Now, as shown in FIG. 3, addresses O to 639 of the refresh memory 6 contain a character code C corresponding to the display character A at each display address on the cathode ray tube 1.
It is assumed that character codes C640 to C663 corresponding to display characters B to be transferred to the printer 10 are stored in advance in addresses 640 to 663 of the refresh-L memory 6. .

In this state a3, the above CR-I-::+nt1''-
As shown in FIG. 2, from address O to address 663 from the first display character line to the last display character line
However, since the display control section 4 is activated only during the horizontal scanning period (tM), the CRT controller 5 outputs the address signals from address 0 to address 639 in order. The predetermined character codes CO to C639 are read out from the corresponding addresses of the refresh memory 6 and given to the character generator 7, and from the character generator 7, character patterns that are clouded to the predetermined character codes are sequentially generated. 1 to be read
, and each character pattern is displayed on Brown@1 via the parallel series circuit 8 and the video control circuit 9.

Furthermore, since the j-address signals at addresses 640 to 663 that are output from the CR1-control 1 caller 5 are those during the horizontal retrace period (THF) of the last display character line, generally the display control unit Although it is not used in d3 in this embodiment, the above address signal can be used in d3. That is, in the horizontal retrace period (thf) of the last displayed character line, the above MP
When the display controller 1 is accessed by U2, character codes C6407 to C663 stored at addresses 640 to 6G3 of the refresh memory 6 are read out and given to the character generator 7. Then, character patterns based on the character codes C640 to C663 are output from the character generator 7, and each character pattern is stored in the buffer memory 14. At this stage lI3, the horizontal scanning signal enters the vertical retrace period (tvr>), so the operation of reading out the character pattern from the character generator 7 in the display 11i+Jtl1 section 4 is completed. Then, MPLJ
2 is changed to 1 by an interrupt signal from the CRT controller 5.
Recognizing the above, the MPU 2 stores it in the buffer memory 14! The c character pattern is read out and transferred to the printer control section 11.

As a result, CRY-Display Mi? The displayed characters ff are reliably transferred to the printer 10.

In the above embodiment, a printer is used as the other output device, but the output device is not necessarily limited to this, and a hard copy device or the like may also be used.

(a) Effects of the Invention -F As explained above, according to the output control method of a display device according to the present invention, when transferring display information of a display device to another output device, the existing display control In this method, an address signal that is not used as an address signal for display information to a display unit is used as it is, and a buffer memory is simply attached to an existing display control unit so that it can be shared as a control unit for other output devices. Therefore, the display information of the display device can be reliably transferred to another output device without unnecessarily lowering the cost of the entire system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall system of a display device for implementing the display device output control method according to the present invention;
FIG. 2 is a schematic diagram showing the characteristics of the display control means used in the present invention, and FIG. 3 is an explanatory diagram showing an example of the contents stored in the refresh memory. 1... Braun tube (display part) 5... CRT-] controller (display control means) 6...
- Refresh memory 7...Character generator (display information generation means) 8...Parallel-serial converter 9...Video control circuit 10...Printer (output device) 11...Printer control section 14...・Buff candy °［
Applicant Fujitsu Limited Figure 2 Figure 3

Claims (1)

[Claims] When transferring display information from a display device to another output device,
During the horizontal blanking period immediately before the vertical blanking period of the display device, display control information for causing display information to be transferred to the output device to be output from the display information generating means is stored in advance in the memory, and the above-mentioned display A display characterized in that the display information is output from the display information generating means according to the control information, the display information is temporarily stored in a buffer memory, and then transferred to the other output device during the vertical retrace period. Equipment output control method.