JPS6247093A - Expanded display control circuit - 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 [Field of Industrial Application] The present invention relates to display control using a code refresh method, and particularly to an enlarged display control circuit.

[Problems to be solved by the prior art and the invention] Conventionally, in screen display using one type of code refresh,
A vertically enlarged display that spans two lines has not been realized. However, in print output, enlarged display in the vertical direction is possible.

Therefore, when enlarging output, there is a drawback that the output format and screen display format do not match.

The present invention aims to provide an enlarged display control circuit using a code refresh method that enables enlarged display in the vertical direction.

[Means for solving problems]

The enlarged display control circuit according to the present invention includes a storage means for enlarged display information read out corresponding to each display character and initial value information of a raster counter, and a storage means for enlarged display information read out from the storage means for each character. and a multiplexer that switches the raster counter value.

It is characterized by comprising an enlargement means comprising an encoder that generates a raster counter value based on the initial value information of the raster counter read from the storage means for each character, and an adder that adds the output of the multiplexer and the output of the encoder. shall be.

〔Example〕

Examples of the present invention will be described below.

The figure is a block diagram of an embodiment of the present invention, in which there are 2 display control units 12, a code buffer 2 serving as a screen memory, and a character inverter 3 for converting codes into dots and turns.
Converting dot pattern data to serial data・2
In addition to the conventional configuration including the parallel/serial converter 4, there is a storage section 5 for enlarged information and initial value information. Multiplexer 6. It consists of an encoder 7° and an enlarging means by an adder 8.

The retrace address 9 and write data 10 output from the display control section 1 are connected to a code buffer 2 and an enlarged information/initial value information storage section 5. An output of the code buffer 2 is connected to a character generator 3, where the code is converted into a dot pattern. The converted dot pattern 17 enters the Noclarel/serial conversion circuit 4, where it is converted into a serial pattern and transferred to the monitor for display.

The connection relationship of raster signals in one row is as follows. A means (
The raster counter value 13 for enlarged display, which is separately created by
It is switched by the multiplexer 6 according to the condition and connected to the adder 8.

Furthermore, the code 15 obtained by encoding the signal 18 output from the initial value information storage section 5 by the encoder 7 is sent to the adder 8.
It is connected to the output from the multiplexer 6 and the lower address of the post-addition character generator 3.

Here, consider the case of 2x enlargement. The enlargement information/initial value information storage unit 5 stores information on whether there is no choice but to enlarge corresponding to the character position to be enlarged, and whether it is the first half or the second half of the character (that is, the upper half or the lower half of one character). I'll keep it.

During enlarged display, a mark appears on signal 19, and multiplexer 6 switches the raster counter value from raster counter value 12 for normal display to raster counter value 13 for enlarged display.

For example, if there are 16 rasks in one row, the raster counter value is 1
2 becomes the four No9 binary signals 20, 21, 22, and 23. In the case of 2x enlargement, raster counter value 13 is set by shifting the signal of raster counter value 12 one step lower to 12'.
It is sufficient to give a signal of +22+23t O. In the case of 2x enlargement, 2 rasks in normal display become 1 rask. Furthermore, since the image is enlarged twice, it is displayed over two lines as usual.

Therefore, when the display of the first line is finished, the enlarged characters are in the middle of the characters. Therefore, it is necessary to correct the raster counter value when displaying the second line. The encoder 7 encodes the sword correction value according to the signal 18 outputted from the initial value information storage section 5 during enlarged display, and the adder 8 corrects the correction value, which is then applied to the character generator 3. The value of encoder 7 is different between the first half and the second half of the character.

In 2x enlarged display, the raster progresses by 1/1 compared to normal display.
2, so at the end of the first line of the normal display, 2
The double-enlarged display is in the middle of the character, and the end of the second line is the end of the double-enlarged display. It is clear that the expansion can be performed not only by 2 times but also by 3 times or more.

〔Effect of the invention〕

As explained above, the present invention stores expansion information and initial value information corresponding to one display character, and uses the stored information to set the raster counter value in units of characters! ;7I replacement
□Also, by correcting the raster counter value and manipulating the lower address to the character generator, □ allows display control using one type of code refresh □
It is also possible to perform enlarged display in the vertical direction.
:

[Brief explanation of drawings]

The figure is a block diagram of one embodiment of the present invention. j
l...display control unit, 2...food buffer, 3...
・K: Yarakuta generator, 4... Relay/serial converter, 5... Expanded information/initial value information storage section, 6... (Multiplexer, 7... Encoder, 8... Adder.'-1-'

Claims (1)

[Claims] 1. In a code refresh type display control circuit, storage means for enlarged display information read out corresponding to each display character and initial value information of a raster counter, and enlarged display information read out from the storage means for each character. a multiplexer for switching the raster counter value accordingly; an encoder for generating a raster counter value based on initial value information of the raster counter read from the storage means for each character; and an adder for adding the multiplexer output and the encoder output. An enlarged display control circuit characterized by comprising an enlargement means including: