Ground Attack

Routines

Address	Description
6800	Blit 8x8 character bitmap at DF offset.
6840	Print fixed length string
685B	Clears the display pixels.
6877	Scan the keyboard.
68A3	Scroll the backgroundscolours left by one column.
68D0	Update the character mapping of the background
68FD	Fill attribute and set border.
6914	Draw the right hand coloumn and scroll screen.
6978	Display the game screen.
69DC	Update the score board on the screen
6A09	Initialises the scoreboard characters.
6A27	Create a random number into A
6A40	Map out right hand column of landscape using tile indices.
6AAE	Updates the items for the next column.
6B6C	initialise the right hand column
6B94	Initilise values for the landscape.
6BD0	Pause loop
6BE4	Start
6C98	Main game update routine.
6D1F	Erase all sprites from screen.
6D88	Routine at 6D88
6D9C	Clear item slots.
6DC4	Draw all of the items.
6DEC	Play sound
6E0A	Routine at 6E0A
6E28	Clear rockets, bombs and lasers if explode.
6E69	Update game keys.
6E8C	Add 10 to the score.
6EA5	Add 100 to score
6EBE	Add 20 to the score.
6F54	Erase each of the items.
6F90	Routine at 6F90
70E4	Check for users input and update the ship.
7210	Move bomb.
72F6	Handler for Bomb 1.
736E	Handler for Bomb 2.
73E6	Display the title screen
749A	Routine at 749A
7508	Handler for the laser.
759E	Game pause (for speed) or play sound
75C6	Screen for selecting game speed.