pouët.net

The goal here was to bring a true arcade experience and make justice to the Amstrad. A 50 frames per second gaming experience. To reach that goal, the characters need to be able to move a half byte at a time otherwise they would go too fast from one side of the screen to the other. So we end up with around 112 giant hard sprites (16 for Ryu, 12 for Retsu, times 2 for the mirroring, times 2 for the half byte precision). They fit in the upper 64kb banks thanks to a custom hard sprite technique which splits sprite data from the sprite drawing code. 32kb are used for the double buffering video. 16kb are dedicated to the background management and the sprite description tables. The lower 16 kb are then available, from which around 8kb are taken by the sprite drawing code, and it remains 8kb for the actual game logic and sound. The scrolling was abandoned because if Rhino's technique of Mario game engine would be reused, it would use a bit more memory for video memory but all memory is already used, and also drawing more background tiles would slow down the game down to 25 frames per second sometimes, depending which sprites are being drawn. However the screen width was left at 40 traditional characters versus 32 in the original.