Changes
/* Implementation details and use of Plus hardware */
* Plus palette is used for the nice colours in the background
* Plus sprites are used for the plane sprite (on the map), the bubbles/balls and the man
* Plus screen split is used for the panel at the bottom(split is set to line 199, so that the split occurs on line 200)* Plus pixel by pixel hardware scroll is not used.
* Some sprites are software sprites (weapons, bird)
