Deathchase

Memory map

Page	Byte	Address	Description
91	0	5B00	Selection of trees to copy to the main playing area.
93	192	5DC0	Enemy bike 1 direction (-1 = left, 0 = centre, 1 = right)
93	193	5DC1	Enemy bike 2 direction (-1 = left, 0 = centre, 1 = right)
93	194	5DC2	Number of frames before enemy bike 1 should change direction
93	195	5DC3	Number of frames before enemy bike 2 should change direction
93	196	5DC4	Number of units to move enemy bike 1 on next frame (negative for left)
93	197	5DC5	Number of units to move enemy bike 2 on next frame (negative for left)
93	198	5DC6	Enemy bike 1 position
93	199	5DC7	Enemy bike 2 position
93	200	5DC8	Bit 0 - Enemy bike 1 running, Bit 1 - Enemy bike 2 running
93	201	5DC9	Control method (0 - keyboard, 1 - kempston)
93	202	5DCA	X offset for bonus enemy
93	203	5DCB	Various status flags
93	204	5DCC	Time (in frames) before a bonus enemy should be drawn
93	205	5DCD	Address to invalidate / redraw bonus enemy on next frame
93	207	5DCF	Counter for random number generator
93	209	5DD1	Current sector (1-8)
93	210	5DD2	Number of enemy bikes still on screen
93	211	5DD3	Bit 1 - night patrol
93	213	5DD5	Distance to next enemy bike frame state (0 - 1E)
93	214	5DD6	Enemy bike frame to draw (0 - far, 1 - medium, 2 - near, 3 - in range)
93	215	5DD7	Firing photon bolt (1 - yes, 0 - no)
93	216	5DD8	x position of photon bolt
93	217	5DD9	Number of frames of photon bolt left to draw
93	218	5DDA	Pointer to next screen offset for photon bolt graphic
93	220	5DDC	Pointer to current photon bolt graphic
93	222	5DDE	Set bit 0 if the photon bolt hit an enemy
93	223	5DDF	Handlebar position (-1 = left, 0 = centre, 1 = right)
93	224	5DE0	Number of frames before shot bike explodes
93	225	5DE1	Position of exploding bike
93	226	5DE2	Pointer to character for next exploding bike frame
93	228	5DE4	Pointer to attribute position for exploding bike frame
93	230	5DE6	Size of playing area - either $01A0 or $02E0
93	232	5DE8	Bike is moving (0 - no, 1 - yes)
93	233	5DE9	The current sector in ASCII format
93	235	5DEB	Set to 1 to mark as "debug mode" - game code can be saved to tape
93	236	5DEC	Current speed (0 - fast, 2 - slow)
94	0	5E00	Move the trees
94	254	5EFE	Check for movement controls
95	40	5F28	Move right
95	71	5F47	Move left
95	102	5F66	Straighten up
95	137	5F89	Print objects on the playing field
96	116	6074	Print the next sector
96	163	60A3	"SECTOR "
96	170	60AA	Play an ascending sound
96	193	60C1	Switch from NIGHT to DAY
97	19	6113	Switch from DAY to NIGHT
97	80	6150	Draw the enemy bikes
97	243	61F3	Recalculate where the enemy bikes should be
98	141	628D	Print "KEYBOARD"
98	152	6298	Print "KEMPSTON"
98	163	62A3	Print the copyright notice
98	174	62AE	See if 1 (keyboard) or 2 (Kempston) was pressed, and start a game if so
98	203	62CB	Switch to a new sector
98	247	62F7	Switch background colour on huge trees between DAY and NIGHT, and initialize the bikes
99	26	631A	Plane graphic
99	42	632A	Plane / tank exploded
99	58	633A	Move a plane or tank across the screen if appropriate
99	113	6371	Set up the play stats
99	124	637C	Move the plane across screen
99	252	63FC	Move the plane
100	46	642E	Draw a bonus enemy
100	83	6453	Move the tank
100	120	6478	Play "enemy bike exploding" sound
100	145	6491	Return a random 8-bit number in A
100	171	64AB	Tree densities for each level
100	179	64B3	Tree densities for each level (not used)
100	183	64B7	Recalculate new tree density based on sector
100	244	64F4	Offsets for screen positions
101	48	6530	Clear the screen
101	127	657F	Main entry point
101	179	65B3	Start a new game
102	61	663D	Main loop
102	157	669D	Check for Kempston input (if configured)
102	175	66AF	Check for keyboard input
102	188	66BC	Speed up
102	204	66CC	Slow down
102	214	66D6	Idle
102	219	66DB	Print the bike's handlebars
102	253	66FD	Collision detection. Did we hit anything?
103	17	6711	CRASH - hit a tree! Bring it close up to the player so we crash into it
103	114	6772	Wipe out playing area
103	129	6781	Play "hit a tree" sequence
103	198	67C6	Make the bikes get nearer or further away
104	2	6802	Track the photon bolt on screen
104	89	6859	Draw trail of photon bolt
104	107	686B	Stop photon bolt (so another can be fired)
104	134	6886	The photon bolt has hit something, find out what
104	240	68F0	See if fire is pressed and if so, set a photon bolt to fire
105	24	6918	Print the bike and static display
105	73	6949	Print a string
105	105	6969	Print the current score
105	116	6974	Print number of lives
105	127	697F	":LIVES : 3:"
105	137	6989	Update the current score
105	142	698E	Update the high score
105	167	69A7	Set up some flags (non useful?)
105	187	69BB	Print the range indicator
105	198	69C6	"[] RANGE"
105	205	69CD	Toggle the range indicator on or off
105	227	69E3	We hit a bike - destroy it
106	40	6A28	Adjust the photon bolt left or right
106	51	6A33	Display an exploding bike
106	122	6A7A	Explosion graphic
106	194	6AC2	Show the enemy bikes pieces shattering
107	56	6B38	"DAY PATROL"
107	68	6B44	"NIGHT PATROL"
107	80	6B50	" 1 = KEYBOARD "
107	92	6B5C	" 2 = KEMPSTON "
107	104	6B68	"GAME OVER"
107	113	6B71	Print that the game is over
107	127	6B7F	Play a descending sound
107	150	6B96	Save the game to tape if bit 0 in 5DEB is reset and P is held down, then S is pressed
107	202	6BCA	":$:000000"
107	211	6BD3	":HI:000000"
107	221	6BDD	Update the highest score to the last score if it is greater
107	252	6BFC	Print the high score
108	7	6C07	Tank graphic
108	23	6C17	Signal bonus
108	58	6C3A	Print bonus message
108	80	6C50	"BONUS!"
108	86	6C56	"(c) MERVYN ESTCOURT 1983"
109	106	6D6A	Offsets for tree graphics (not used)
109	115	6D73	Offsets for tree graphics
109	191	6DBF	Bottom display graphic
112	0	7000	Handlebar graphic - forward
112	126	707E	Handlebar graphic - right
112	252	70FC	Handlebar graphic - left
113	122	717A	Data (not used?)
113	132	7184	Enemy graphic - far left
113	140	718C	Enemy graphic - far centre
113	148	7194	Enemy graphic - far right
113	156	719C	Enemy graphic - medium left
113	164	71A4	Enemy graphic - medium centre
113	172	71AC	Enemy graphic - medium right
113	180	71B4	Enemy graphic - near left
113	196	71C4	Enemy graphic - near centre
113	212	71D4	Enemy graphic - near right
113	228	71E4	Enemy graphic - in range left
113	244	71F4	Enemy graphic - in range centre
114	4	7204	Enemy graphic - in range right
114	20	7214	Photon bolt graphic
114	70	7246	Tree (huge)
115	138	738A	Tree (huge)
116	206	74CE	Tree (large)
117	112	7570	Tree (large)
118	18	7612	Tree (large)
118	180	76B4	Tree (large)
119	86	7756	Tree (large)
119	248	77F8	Tree (large)
120	154	789A	Tree (small)
120	208	78D0	Tree (small)
121	6	7906	Tree (small)
121	60	793C	Tree (small)
121	114	7972	Tree (small)
121	168	79A8	Tree (small)
121	222	79DE	Tree (small)
122	20	7A14	Tree (small)
122	74	7A4A	Tree (small)
122	128	7A80	Tree (small)
122	182	7AB6	Tree (small)
122	236	7AEC	Tree (small)
123	34	7B22	Tree (small)
123	88	7B58	Tree (small)
123	142	7B8E	Tree (small)
123	196	7BC4	Tree (beyond horizon)
123	250	7BFA	Storage for small tree graphic
124	39	7C27	Storage for tree graphic
124	161	7CA1	Visible tree positions, in a grid 20 across 24 back to front.