Help, my left and right buttons cannot work simultaneously with the B key

[geek-sc]

Help, my left and right buttons cannot work simultaneously with the B key, but the left and right buttons of the joystick can work simultaneously with the B key. The reason I currently know is that there may be a problem with the kernel file, but I don't know how to modify it. I know its file name is ZImage, and my machine model number is RS-77