JPH05108048A - Crt display device - Google Patents

Abstract

PURPOSE:To make a freely selective display and increase the number of kinds of display patterns by providing plural kind of character generators(CG). CONSTITUTION:This CRT display device has a positive CG 2, a negative CG 3, a RAM CG 4, an attribute CG 5, a CG selecting circuit 6 which selects those four kind of CGs 2, 3, 4, and 5, a display circuit 7 which displays the selected CG on a CRT 10, a CRT control code generating circuit 8 which sends a control code and address data to the selected CG and sends CG data to the display circuit 7, and a data processor 1 which controls the whole; and characters, symbols, etc., from the CG selected by the CG selecting circuit 6 are displayed on the CRT under the control of a data processor 1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a CRT display device.

[0002]

2. Description of the Related Art In a conventional CRT display device, the contents of a character generator (hereinafter referred to as CG) ROM are normally displayed as they are, and for example, only a CGROM for positive display is provided, and one dot "ON" when negative display,
The display was performed by reversing "OFF", and in the case of the negative display, the brightness was reduced to some extent.

[0003]

DISCLOSURE OF THE INVENTION The conventional CRT described above
Since the display device reads and displays the contents of one type of CGROM, in the case of reverse display at the time of negative display, there is a drawback that thin lines are crushed or partially darkened. To use. CGROM
However, there is a drawback that only the CG written in CG can be displayed, and like the stroke CG, the CG cannot be dynamically expanded according to the purpose of use of the user, or cannot be displayed in ad tribute.

[0004]

A CRT display device of the present invention comprises a positive character generator, a negative character generator, a RAM character generator, an attribute character generator,
It has a selection circuit for selecting any of these four types of character generators, and a display circuit for performing display by the character generator selected by this selection circuit.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, this embodiment shows a positive CG.
2, negative CG3, RAMCG4, attribute CG5, and these four types of CG2, 3, 4, 5
CG selection circuit 6 for selecting the selected CG and the selected CG
10, a display circuit 7 for displaying, a CRT control code generating circuit 8 for sending control code and address data to the selected CG and sending CG data to the display circuit 7, and a data processing device for controlling the entire embodiment. 1 and are configured.

Next, the operation of this embodiment will be described.

First, the data processing device 1 writes data according to the user's purpose into the RAMCG 4 by using the address bus 104 and the data bus 103. The content of this data may be stroke CG, or 16
CG of x16 dots, 24x24 dots, or 28x28 dots may be used.

Next, the data processing apparatus 1 has the CG selection circuit 6
Is operated to select one of the positive CG2, the negative CG3, the RAMCG4, and the stroke CG5 by using the control signals 12, 13, 14, and 16.

Next, the data processing device 1 sends a control signal 15 corresponding to the selected CG to the CRT coat roll code generation circuit 8. The CRT control code generation circuit 8 generates an address and control code for the selected CG and sends it to the selected CG, and also sends address data to the display circuit 7, and the CRT display circuit 7 changes the selected CG from the selected CG. The characters, symbols, etc. are displayed on the CRT 10.

[0012]

As described above, the present invention has four types of C.
By having G and having a configuration in which these CGs are selected by a selection circuit, positive or negative,
A stroke CG and an attribute are selected according to the user's purpose of use, and thus a dynamic and easy-to-see CRT display can be made possible, and the CG can be expanded.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 Data Processing Device 2 Positive Character Generator (CG) 3 Negative Character Generator (CG) 4 RAM Character Generator (CG) 5 Character Generator for Attribute (C
G) 6 CG selection circuit 7 display circuit 8 CRT control code generation circuit 10 CRT 11-16 control signal 101, 103 data bus 102, 104 address bus

Claims (1)

[Claims] 1. A positive character generator,
It has a negative character generator, a RAM character generator, an attribute character generator, a selection circuit for selecting any of these four types of character generators, and a display circuit for performing display by the character generator selected by this selection circuit. A CRT display device characterized by the above.