Abstract: A memory cartridge is loaded in a main unit of a personal computer when used. The memory cartridge comprises a case, and a printed circuit board which is installed therein and on which a large-capacity, one-chip ROM is mounted. Storage area of the one-chip ROM is divided into a plurality of banks respectively having memory addresses of a number accessible by a central processing unit of the main unit, and one specific bank among them is allocated to an address space accessible all the time by the central processing unit. Bank selecting data for selecting other banks is stored in that specific bank. The bank selecting data is read out with progress of a program stored in the specific bank, being loaded in a counter. The content of the counter is inputted to the most significant three bits of address of the one-chip ROM. The most significant three bits of the address function as bank designating bits.

Abstract: A game software service system is connected to a monitor to display an image for game. A CPU and a PPU which cooperates with the CPU are accommodated within a housing. A plurality of storage mediums which respectively store game programs are attached to the housing in an attachable/detachable manner. The respective storage mediums are commonly connected to an address bus and a data bus of the CPU and the PPU, and assigned with a common address space. A first controller is used for playing a game. Any one of the storage mediums is selected by operation of a second controller. When a menu showing a plurality of game names is displayed on the monitor, accesses from the CPU and the PPU to a selected storage medium are enabled in response to the operation of the second controller. The CPU and the PPU execute a program of the selected storage medium to display the image for game on the monitor.

Abstract: A cartridge for a gaming machine includes a case having tapered surface formed along a side edge of the rear face thereof which cooperates with a protrusion in the cartridge receiving tray in the gaming machine main unit to prevent an inverted insertion of the cartridge into the machine. A character ROM, a first semiconductor memory storing a program for determining authenticity of the cartridge and a first microcomputer for executing that program are mounted on a printed circuit board accommodated in the case. The gaming machine includes a picture processing unit generating an image signal based on data from the character ROM, a second semiconductor memory which stores the same program for determining authenticity of the cartridge as the program in the first semiconductor memory, and a second microcomputer identical to the first microcomputer for executing the program stored in the second semiconductor memory. The second microcomputer determines authenticity of the loaded or inserted cartridge.

Abstract: A shooting game apparatus to project a target and a pair of bullets on a screen. Upon firing a gun, a pair of bullets will move on the screen toward the target giving a feeling of real air fights. The apparatus comprises a housing, a light source disposed in the house, a pair of bullet forming units placed in the sides of said light source in a symmetrical fashion including a bullet slit, a mirror and a lense, said units being rotatable around said light source in said housing, and a means for driving said units rotating around said light source, whereby a pair of bullets are projected and moved on a screen in a symmetrical fashion.