1. Field of the Invention
The present invention generally relates to a game signal conversion apparatus. More specifically, the present invention relates to a game signal conversion apparatus which makes a cartridge for a first game machine usable in a second game machine having a processing ability for image display such as the number of colors, speed and etc. which is different from the processing ability of a first game machine.
2. Description of the Prior Art
Exemplary prior art game machines include: an 8-bit hand-held game machine with liquid crystal display which displays a game image in gradation with utilizing a monochrome dot-matrix liquid crystal display (e.g. "GAME BOY" which is manufactured and sold by the same assignee as that of the present invention), an 8-bit television game machine (e.g. "FAMILY COMPUTER" or "Nintendo ENTERTAINMENT SYSTEM" which is manufactured and sold by the same assignee as that of the present invention), and a 16-bit television game machine (e.g. "SUPER FAMICON" or "SUPER Nintendo ENTERTAINMENT SYSTEM" which is manufactured by the same assignee as that of the present invention). In the above described 8-bit television game machine, in displaying an image of one character, one of four (4) colors can be designated for each dot of the character, and by combining color tone data designating one of the four colors and color palette data, it is possible to display the image with a maximum 54 (fifty-four) colors for a whole screen. In contrast, in the above described 16-bit television game machine, by changing a mode, it is possible to select the number of colors capable of being utilized in displaying an image of one character out of 4-color, 16-color and 256-color, and therefore, it is possible to select 256 colors for a whole screen out of 32768 colors at maximum by combining data for designating a color tone (color tone data) and color palette data.
In the conventional game machines, there was no compatibility for game software between game machines having processing abilities (e.g. the number of bits, the processing speed, the number of colors and etc.) of microprocessors or CPUs different from each other. Therefore, it was impossible to use a cartridge which stores a game program developed for a given kind of game machine in another kind of game machine even if a form or dimension of the cartridge for the given kind of game machine is made equal to a form or dimension of a cartridge for the other kind of game machine. For example, a cartridge for the game machine with dot-matrix liquid crystal display (e.g. the above described "GAME BOY") could not be applied to the television game machines capable of displaying the image in color (e.g. the above described "FAMILY COMPUTER" and "SUPER FAMICON"). Furthermore, even if a CPU or microprocessor having the same number of bits is utilized, since character data stored in a memory (ROM) contained in the cartridge is only data for displaying the image in monochrome with gradation, it is possible to display the image with only a single color having a plurality of gradations. Furthermore, a cartridge for the 8-bit television game machine could not be utilized in the 16-bit television game machine even if the form of the cartridge, the number of pins and an arrangement of the pins of the cartridge for the 8-bit television game machine are made the same as that of a cartridge for the 16-bit television game machine because the structure of data for designating the color or color tone are different from each other.
On the other hand, in a case where the cartridge for a given kind of game machine is used in another kind of game machine, in order to secure adaptability, it is necessary to change a portion of the specification of the cartridge. In such a case, it was difficult to input data for changing a portion of the specification. Especially, in a case of a game machine, the game machine has no keyboard in contrast with a personal computer, and therefore, data entry utilizing a game controller becomes complex, and operation thereof becomes troublesome.