JPH045475B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a read-only memory used, for example, in a signal generation circuit for a CRT display.

Home video games, which are played using home television receivers, are attracting attention. In other words, video game devices have traditionally been installed and used in play areas, etc., but video game devices can also be sent to home television receivers to display images on the screen and even output audio to enjoy the game. Devices have only recently begun to be developed.

And for enjoying home video games
A circuit shown in FIG. 1 is known as a signal generating circuit for a CRT display.

This circuit will be briefly explained below. 1 is
It is a CPU (central processing unit) and has a read-only memory (hereinafter referred to as ROM) in which programs common to various games are written in addition to normal functional blocks. 2 contains a program specific to one game actually played. A code generator 3 generates a coded signal based on the output signals of the CPU 1 and the ROM 2. The code generator 3 accesses any character from the ROM 4 in which various characters (alphabetic characters, kanji, numbers, symbols, etc.) are written, and generates a coded signal that can be sent to the next stage. The ROM 4 stores all the characters required for various games, and sends the character specified by the output of the code generator 3 to the interface (TV-IF) 5, and further outputs the output of this interface 5. CRT via modulation circuit MOD6
(cathode ray tube) as a video signal. In this circuit, when changing the content of a game, the ROM 2 storing a program specific to the game is replaced, and by preparing multiple types of ROM 2, it is possible to enjoy the same number of games.

By the way, in such a signal generation circuit for a CRT display, a ROM for character storage is used.
Only the types of characters stored in ROM 4 can be drawn on the CRT, and in order to enjoy many games, it is necessary to increase the storage capacity of ROM 4 for character storage, and in response to this, it is necessary to increase the storage capacity of ROM 4 for character storage. The amount of code to remember also increases. Also, depending on the restrictions on the codes that can be used, it will be compatible with new games that will appear in the future.
It may become impossible to create ROM2.

The present invention has been made to solve these problems, and one purpose of the present invention is to reduce the storage capacity of a storage device used in a CRT display signal generation circuit. The goal is to increase the versatility of the circuit.

One embodiment of the present invention to achieve the above object is a replaceable read-only memory that stores programs and pattern information specific to a particular application.

The present invention will be explained below with reference to Examples.

FIG. 2 is a block diagram showing a CRT display signal generation circuit to which the present invention is applied.

1 is a CPU (central processing unit). In addition to normal functional blocks such as arithmetic circuits and various registers, this CPU also includes a system monitor ROM that contains programs common to various games, i.e., a ROM that contains pattern memory control programs and key control programs. There is.

7 stores a game program specific to one game actually played, character codes such as characters and symbols required for the game, and a character exchange code generator.

Further, the present invention does not have a dedicated code generator for generating character signals.
After all, there is simply a code generator unique to each game in the ROM 7 prepared for each game.

A pattern memory 8 stores the code-converted patterns in the ROM 7, and functions as a refresh memory. The pattern stored here is the exact pattern that can be drawn on the CRT screen by sending a video signal to the CRT via the TVIF5 and MOD6. 5 is an interface TVIF interposed between the refresh pattern memory and the television receiver, which reads from the pattern memory 8 and converts it into serial data;
Performs synchronization signal generation, color control, etc.
6 is a circuit that receives the signal from TVIF 5 and modulates it with each carrier wave.

According to the read-only memory of the present invention, each game is provided with a program specific to that game as well as a code generator for the characters required for that game. There is no need to consider character codes necessary for various games that exist in non-replaceable parts of the signal generation circuit. That is, when a character code is set in a non-replaceable part, it becomes necessary to create a program while checking the presence or absence of the existing character code, which makes the program creation extremely complicated. In addition, game programs are limited to the range of existing character codes. On the other hand, in the ROM of the present invention, the characters necessary for the program can be prepared at the same time when the program is created, so the program can be created extremely easily. Accordingly, the ROM of the present invention is extremely easy to design and manufacture.

Furthermore, with conventional game ROMs, only the types of characters written in the character storage ROM installed in the CRT display signal generation circuit are available.
However, since the read-only memory of the present invention allows a wide variety of character settings for each game, it is possible to draw a wide variety of characters on a CRT according to each game. , making it possible to create a wide variety of games that will be developed in the future.

The present invention is not necessarily limited to games, but can also be used for educational purposes, for example, and can be generally applied to signal generation circuits for CRT displays.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional example, and FIG. 2 is a block diagram showing a display device to which the present invention is applied. 1...CPU, 2...Game-specific program built-in ROM, 3...Code generator, 4...
ROM, 5...TVIF, 6...MOD, 7...Game-specific program, character storage
ROM, 8...Refresh pattern memory.

Claims (1)

[Claims] 1. A read-only memory that is replaceably provided to a display device including a processing unit equipped with a read-only memory for system monitoring, which includes a program specific to a specific application and a pattern that should be directly displayed on the display device. A read-only memory characterized in that character information that has been created is written into it.