Ground Attack

Memory map

Page	Byte	Address	Description
104	0	6800	Blit 8x8 character bitmap at DF offset.
104	64	6840	Print fixed length string
104	91	685B	Clears the display pixels.
104	119	6877	Scan the keyboard.
104	163	68A3	Scroll the backgroundscolours left by one column.
104	208	68D0	Update the character mapping of the background
104	253	68FD	Fill attribute and set border.
105	20	6914	Draw the right hand coloumn and scroll screen.
105	120	6978	Display the game screen.
105	220	69DC	Update the score board on the screen
106	9	6A09	Initialises the scoreboard characters.
106	39	6A27	Create a random number into A
106	64	6A40	Map out right hand column of landscape using tile indices.
106	174	6AAE	Updates the items for the next column.
107	108	6B6C	initialise the right hand column
107	148	6B94	Initilise values for the landscape.
107	208	6BD0	Pause loop
107	228	6BE4	Start
108	152	6C98	Main game update routine.
109	31	6D1F	Erase all sprites from screen.
109	136	6D88	Routine at 6D88
109	156	6D9C	Clear item slots.
109	196	6DC4	Draw all of the items.
109	236	6DEC	Play sound
110	10	6E0A	Routine at 6E0A
110	40	6E28	Clear rockets, bombs and lasers if explode.
110	105	6E69	Update game keys.
110	140	6E8C	Add 10 to the score.
110	165	6EA5	Add 100 to score
110	190	6EBE	Add 20 to the score.
111	84	6F54	Erase each of the items.
111	144	6F90	Routine at 6F90
112	228	70E4	Check for users input and update the ship.
114	16	7210	Move bomb.
114	246	72F6	Handler for Bomb 1.
115	110	736E	Handler for Bomb 2.
115	230	73E6	Display the title screen
116	154	749A	Routine at 749A
117	8	7508	Handler for the laser.
117	158	759E	Game pause (for speed) or play sound
117	198	75C6	Screen for selecting game speed.
119	157	779D	Strings for select speed screen.
119	241	77F1	Attribute values for title screen.
120	86	7856	Fixed length strings.
120	197	78C5	Characters / Colours used to draw each item
120	227	78E3	Values for keys being pressed during game.
121	1	7901	Copy of items positions.
121	61	793D	Postions of items
121	120	7978	Colour mapping for background
124	57	7C39	Data block at 7C39
124	59	7C3B	Data block at 7C3B
124	72	7C48	String for the score board.
124	106	7C6A	Character map for the screen.
127	88	7F58	Game graphics