Routines

Address	Description
24703	Start of game, from LOADer and new game loop
24795	Move aliens along, based on speed control value
24823	Reset game data
24835	Initialise new screen data
24868	Dynamic pause
24908	delay_ms (approx)
24919	Advance alien start row
24935	Print score
24989	Reset score, update high score
25034	Draw lives remaining on top row
25105	Award extra life
25160	Game over
25228	Initialise game screen attributes
25442	Spaceship handler
25592	Hit spaceship
25628	Spaceship noise
25643	Spaceship has been hit, award bonus
25686	Add A to HL (1)
25708	Move alien bullets.
25737	Advance IX to point to next alien bullet slot
25749	Generate alien bullets
25853	Move alien bullet
25976	Clear alien bullets
25994	Increment alien bullet position
26001	Clear bottom character row
26020	Remove alien bullet
26038	Has an alien been hit?
26049	Bullet and alien collision check, Y axis
26154	Bullet and alien collision check, X axis
26225	Alien hit
26320	Alien hit, zero out the UDGs
26337	Draw alien explosion
26375	Recalc alien numeric data on alien hit
26464	Increase score when alien hit
26484	Add A to HL (2)
26490	Player bullet interception detection
26566	Handle player inputs.
26587	Keypress detection
26675	Redraw player ship
26712	Select player ship clear sprite data
26883	Fire pressed
26916	Draw the player bullet.
26947	Clear player bullet
26965	New player ship
27005	Copy alien UDG data to a screen row
27030	Initialise alien position data
27097	Find the data structure which represents the row of aliens
27114	Find alien UDG data
30857	Move aliens
30995	Move one row of aliens down
31075	Initialise draw aliens
31119	Prepare alien row drawing data
31198	Print one row of aliens
31257	Draw an alien sprite scan line
31290	Set INK colour of attributes
31303	Set alien colour band
31327	Remove barriers when the aliens get low
31436	Draw barriers
31527	Has bullet hit a barrier?
31634	Set pixel
31640	Clear pixel
31647	XOR pixel
31653	Clear screen byte but leave pixel
31922	pxy2saddr
31960	Draw or undraw sprite
31987	Sound burbler
32034	Click speaker bit, causes 2 clicks separated by the given pitch
32059	Update cycler values
32127	Generate printable score
32159	Find digit char UDG
32254	cxy2saddr
32275	Print UDG at HL to screen at BC
32287	Clear screen pixel data
32302	Print string at return address
32307	Print positioned string at HL
32311	Print string at HL
32343	Attribute address finder, cx,cy to attr address
32362	Update pixel
32374	Prime pixel update
32398	Find character