Fruit Mazes

Fruit Mazes is a simple game for MSX 1, in a 16kb ROM using 16kb of RAM. The goal of the game is to navigate the maze in each stage and pick up all of the fruit in the maze within ten minutes, without touching the walls. It features omnidirectional smooth scrolling, which is not typical of MSX 1 games since hardware scrolling is not a feature of the TMS9918 video chip used in MSX 1 computers. The scrolling is achieved by pre-generating multiple sets of patterns, one set for each vertical scroll offset modulo 8, and by setting the TMS9918 pattern base address correspondingly. The game also has accurate roll-on/roll-off of sprites at all sides of the viewport, achieved by setting the EC bit on every sprite and by pre-generating copies of the sprite patterns with pixels masked out from the right. There are twelve stages, the second set of six stages has narrower corridors.