JPS589193A - Crt display - 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 The present invention relates to a CRT display device using a refresh memory, in which the contents of the refresh memory are not changed and can be converted on the real coordinate origin of the display screen.

In recent years, the price of semiconductors has been decreasing, and even among low-cost computers, the number of models that can display graph ink is increasing.

The language used is a general-purpose language such as RASIC, and most of them are compatible, but the display screen controls such as the configuration of the address counter of the special KCRT controller are different. It cannot be ported to other devices. One of them is the actual coordinate origin position of the display screen. The number of pixels on a graphic screen varies depending on the model; for example, in the case of 500 x 200 pixels, it is a matrix screen with 500 pixels in the X direction and 200 pixels in the y direction, and the plotting position is determined by (x, y). To explain in terms of 1E, in the 1-by-1 method, the origin position (0, 0) on the CRT display screen is As shown in t-b, it is set at the upper left corner of the screen, and the y direction advances from top to bottom (most common in C character displays).

Another method is explained with reference to Fig. 2. In a state where straight line information is stored in the refresh memory as shown in Fig. a, the actual origin position (0, 0) on the CRT display screen is changed as shown in Fig. B. As shown, there is a setting in the lower left corner where y advances upwards from the 19th F (suitable for displaying graphs, etc.), but either method 4 The information stored in the refresh memory and the plot on the display screen do not match. There is. Which is advantageous depends on the application. Therefore, it is convenient for the user to be able to arbitrarily select either method. .

It is possible to convert coordinates using software, but this requires rewriting the refresh memory plot to correspond to the address counter's counting method (K), which is difficult in terms of software compatibility and overhead time. It is disadvantageous.

The present invention relates to a CRT display device that eliminates the above-mentioned drawbacks by making it possible to change the origin of actual coordinates on the display screen without changing the contents of the refresh memory.

The present invention will be described in detail below based on embodiments shown in the drawings.

3rd eli! Embodiment 1 of the present invention will be described from I onwards. That is, Fig. 3 shows the straight line information stored in the 7-receiver memory, and the position of the dot on the CRT display screen is taken in the same manner as shown in Fig. 1, as shown in Fig. 3-b. The display output can be obtained, and the 215th! ! This shows that the display output as shown in FIG. 3CK can be obtained by requesting the same as Ib. As described above, according to the present invention, it is possible to select large displays with different origins from the same refresh memory.

4. To explain in more detail, as shown in FIG. When scanning from left to right and from top to bottom as shown in section 4156b, the refresh memory and display screen plots correspond, but when scanning from the refresh memory shed to the right and from bottom to top as shown in section 4156bK. The coordinates are transformed.

5 - FIG. 5 is a block diagram of a CRT display device, where t61 is a refresh memory, that is, a RAM that stores patterns to be displayed, and an MPU (microprocessor fz unit) 2 writes rehearsal data. 3 is a rounded CRT that is written in refresh memory and displays 9 patterns kcRTK
It is a controller. Pattern #1 of the refresh memory 1 is converted into a 7-real signal by the parallel-to-serial converter 4 under the control of the RT controller 30 and displayed on the CRT 6 via the video controller 5.

In addition, the selection is made on the input signal to the lotus 7 letter S/emory l indicated by 1-1! Ruchipurekuna and 4-1 are bus drivers.

Also, video from CRT controller 3;
The signals output to are a timing signal bottle, a horizontal pivA signal, and a vertical synchronization signal, respectively.

6- FIG. 6 is a block diagram of a scan control section that determines the scan address of the CRT controller I-3. 7 is the start address register of the refresh memory 1) It is used to set the snode address of the refresh memory 1 corresponding to the first or most significant raster on the display screen. If the origin coordinates on the display screen are at the upper left corner, the first address of the refresh memory is @0'', and if it is at the lower left corner (refresh memory final address - (l raster compatible memo 9
The value of M-1)) is set. At the end of scanning one rask, the number of addresses to be added is set in the 8-company vertical addition register to point to the next 2 star start address t. If it is the origin or the upper left corner, it is + (number of 1 cluster memory)),
When the origin is at the lower left end, - (15 number of star memories). 1
0 is the 2-star start address register, and 6D is set to the start address L/2 of the next disk. At the end of one scan, the contents of the raster start address register 1o and the vertical addition register 8 are added by an adder 11, and the contents of the raster start address register 1o and the vertical addition register 8 are added together to become the start address of the next scan.
OK is set. When the raster start address is set, the linear address generator 12' is activated and
Addresses the raster minute fresh memory in a linear manner. The horizontal counter 13 counts t the number of output pixels for 1 raster, and the horizontal scan number comparison circuit 14 determines that the 1 raster has ended and activates the adder 11. When the scan of the last raster of the refresh memory is completed, the raster start address register 10 is reset, the value of the start address register is set in the raster start address register again, and scanning is started again.

As described above, when the origin is at the upper left end, the connection from one raster to the next raster increases linearly as an address on the search memory. In the case of the lower left end, as soon as the scanning of 2 stars is completed, the start address t points of 1 raster before the refresh memory. As a result, the scanning method shown in FIG. 4 becomes possible.

The operation of the present invention will now be explained in more detail with reference to FIGS. '- In the explanation, as shown in No. 7-, <CRT raster at-
30, and the number of pixels of the 1'7 star is 4'0.

The operator naturally knows which type of up force the program is for, as shown in Figure 8, and it is assumed that the program to be used now is for the up counter as shown in Figure 8. (Set as A mode 9-). In this case, the operator uses a setter (not shown) to set the start address register 7 to @0"t [see Figure 6], and uses a setter (not shown) to set the addition register 8 to "40"t. Therefore, the raster start address register 10 is @O'', and the linear address register 12 is synchronized with the CRT control memory and read signal. The count is sequentially increased from ``up'' and the refresh memory lk (see M3rjA) is counted up from the small address to the large address.
read out. Now, the linear address register, N=ri12
The number of output pixels read out is counted by a horizontal counter 13,
Number of output pixels set in vertical addition register 8'''4
When the horizontal scan number comparator circuit 14 detects a match with 0'', it multiplies the adder 11 with #ht-, and the raster start, a, tonire!, 10-@(in PI) of the two registers 19 is detected. @01) and the vertical addition register 8 (#i@4O- in the example) k is added, and @40'' is set in the 2-star start address register 10.

Next, the content t of the raster start address register 1o is set to 4 in the linear address register 12, and the content of the raster start address register 1o is set to 4.
Start from address 0. In this way, the raster start address register 1o and the vertical addition register 8 are sequentially added each time the horizontal scan comparator circuit 14 issues a start signal, and the point address of the refresh memory 1 by the linear address register 12 is advanced. When scanning for one screen is completed, raster start address register 1
0 is reset to zero.

When the next program to be used is for a down counter (B mode) (see Figure 9), the operator uses a setting device (not shown) to start address register yKxxe9-(
4o2x)-1160 is set. Then, a setter (not shown) sets the Im direct addition number register 8 to °-40''t. In this case, when the 41 rast scan is completed, 1160 C-40) is performed in the adder 11, and the 2 star start address Set as the start address of register 120Yr12 las scan, linear address generator/12#i 22nd star scan 1-112
Readout sequentially from address 011 to address 1159.

As is clear from the above description, (1) according to the present invention, it is possible to change the actual coordinate origin of the display screen without changing the contents of the refresh memory, excellent effects can be obtained in graphic processing, and hardware This makes it possible to improve program compatibility in terms of software.

[Brief explanation of the drawing]

Figures 1111 to 3 are relationship diagrams between the refresh memory and the display screen. b is a relational diagram showing the conventional example, 3rd diagram, b and t are the present invention o
- A diagram of the relationship between the refresh memory and the display screen according to the implemented IPIK; Figures 4a, b, and c are diagrams of the relationship between the refresh memory and the scan method of the display screen according to an embodiment of the present invention; Figure S is the control of the CRT display device; Circuit block diagram, 116
&4 is a block diagram of the scan control unit of the cRT controller, Figure 87 is a diagram showing the relationship between raster scan and refresh memory addresses, Figure 8 shows a display screen where the raster scan start address is 101 in Figure 5, and 13 - The ninth factor shows a display screen where the raster scan start address is @1160'' in FIG. 7. 1...Refresh memory 2-MPU3...
・CRT controller 5...video controller 6
...CRT? -...Start address register 8...Vertical addition register 10...Raster start address register 11...
Adder 12--Linear address generator 13--Horizontal pixel counter 14--Horizontal scan number comparison circuit Patent applicant Canon Corporation 14- 6'c! 3 Figure 5 Figure 9 Figure 8

Claims (1)

[Claims] A setting means for setting the start address of the 7-receiver memory corresponding to the origin of the display screen, a setting means for setting an update value of the read address of the refresh memory required to proceed with raster scanning, and each of the above two setting means. A CRT display device comprising means for determining a read start address of the refresh memory corresponding to a start address of a two-star scan.