Asteroids RAM Usage

00	$00
01	$01
02	$02
03	$03
04	$04
05	$05
06	$06
07	$07
08	$08
09	$09
0A	$0A
0B	$0B
0C	$0C
0D	$0D
0E	$0E
0F	$0F
10	$10
11	$11
12	$12
13	$13
14	$14
15	$15
16	$16
17	$17
18	curPlayer	Current Player (0 = Player 1, 1 = Player 2)
19	$19
1A	numPrevPlayers	Number Of Players In Previous Game (0 = None, 1 = Singleplayer, 2 = Multiplayer)
1B	$1B
1C	numPlayers	Number Of Players In Current Game
1D:30	highScores	High Score Table (Scores) 2 Byte Format In Decimal. Byte 1 Tens, Byte 2 Thousands (In Decimal)
31	highScoreLetter	Current Letter On High Score Entry
32	ply1HighPlacement	Placement Of Player 1 High Score
33	ply2HighPlacement	Placement Of Player 2 High Score
34:51	highScoresInitials	High Score Table (Initials) 3 Byte Format
52	ply1ScoreTens	Player 1 Score Tens (In Decimal)
53	ply1ScoreThous	Player 1 Score Thousands (In Decimal)
54	ply2ScoreTens	Player 2 Score Tens (In Decimal)
55	ply2ScoreThous	Player 2 Score Thousands (In Decimal)
56	numShipsPerGame	Number Of Starting Ships Per Game
57	ply1CurShips	Current Number Of Ships, Player 1
58	ply2CurShips	Current Number Of Ships, Player 2
59	hyperSpaceFlag	Hyperspace Flag: 1 = Successful Hyperspace Jump, $80 = Unsuccessful Hyperspace Jump (DEATH), 0 = Hyperspace Not Currently Active
5A	delayBeforePlay	Time before game starts/time in 2 player game before it switches from current player to next after current player death. Starts at #$80 and counts down to 0
5B	??timeout??	?? Appears to be a timeout for the code. Game will lock up if this goes above 3. Checked in the NMI
5C	fastTimer	Fast Timer
5D	slowTimer	Slow Timer
5E	$5E
5F	rndValue	"Random" Value
60	$60
61	direction	Ship Direction
62	saucerShotDir	Direction Shot Is Fired From Saucer
63	photomLimiter	Photon Input Limiter (0 = No Input, +128 Per Photon, 255 = Max Input Limit) can't shoot a photon if value is above 127. Also used for initials input length on high score entry
64	ship_thrust_dH	Ship Horizontal Velocity Low
65	ship_thrust_dV	Ship Vertical Velocity Low
66	sndTimePlayerFire	TIMER: Length Of Time To Play Player Fire Sound
67	sndTimeSaucerFire	TIMER: Length Of Time To Play Saucer Fire Sound
68	sndTimeBonusShip	TIMER: Length Of Time To Play Bonus Ship Sound
69	sndTimeExplosion	TIMER: Length Of Time To Play Explosion Sound
6A	sndAltFirePlayer	Alternate Fire Sound Flag For Player
6B	sndAltFireSaucer	Alternate Fire Sound Flag For Saucer
6C	sndThump	Current Volume & Frequency Settings For THUMP Sound
6D	sndThumpOn	TIMER: Time THUMP Sound Remains On
6E	sndTHumpOff	TIMER: Time THUMP Sound Remains Off (Speeds Up As Game Progresses)
6F	holdLampValues	Bitmap Of Changes To Be Made In $3200
70	numCredits	Current Number Of Credits
71	holdDIP	Bitmap Of DIP Switches 4-8
72	slamFlag	Slam Switch Flag
73	coinsToCredits	Total Coins (After Multipliers) To Be Converted To Credits
74	$74
75	$75
76	$76
77	$77
78	$78
79	$79
7A	coin1InpLen	Coin 1 Input Length (31 = No Input) goes down by 1 until it hits 0, if input is released before 0 then credit is added
7B	coin2InpLen	Coin 2 Input Length
7C	coin3InpLen	Coin 3 Input Length
7D:88	$7D	Ship explosion pieces x offsets (byte 1 minor, byte 2 major)
89:94	$89	Ship explosion pieces y offsets (byte 1 minor, byte 2 major)
95:FF	$95
0100:01FF	stack	Stack Space

0200 - 02FF Current Player RAM

0200 - 0222 Status

0200:021A	statusAsteroids	Asteroids 27-1
021B	statusShip	Ship, 0 = No Ship Or Currently In Hyperspace, 1 = Alive, 0x160+ = Ship Currently Exploding
021C	statusSaucer	Saucer, 0 = No Saucer, 1 = Small Saucer, 2 = Large Saucer
021D:021E	saucerShotTimer	Saucer Shots 2-1 Countdown Timer
021F:0222	shipShotsTimer	Ship Shots 4-1 Countdown Timer

0223 - 0245 Horizontal Velocity 0-255, (255-192) = Left, 1-63 = Right

0223:023D	horzVelAsteroids	Asteroids 27-1
023E	horzVelShip	Ship
023F	horzVelSaucer	Saucer
0240:0241	horzVelSaucerShots	Saucer Shots 2-1
0242:0245	horzVelShipShots	Ship Shots 4-1

0246 - 0268 Vertical Velocity 0-255, (255-192) = Down, 1-63 = Up

0246:0260	vertVelAsteroids	Asteroids 27-1
0261	vertVelShip	Ship
0262	vertVelSaucer	Saucer
0263:0264	vertVelSaucerShots	Saucer Shots 2-1
0265:0268	vertVelShipShots	Ship Shots 4-1

0269 - 028B Horizontal Position High (0-31), 0 = Left, 31 = Right

0269:0283	hposhAsteroids	Asteroids 27-1
0284	hposhShip	Ship
0285	hposhSaucer	Saucer
0286:0287	hposhSaucerShots	Saucer Shots 2-1
0288:028B	hposhShipShots	Ship Shots 4-1

028C - 02AE Vertical Position High (0-23), 0 = Bottom, 23 = Top

028C:02A6	vposhAsteroids	Asteroids 27-1
02A7	vposhShip	Ship
02A8	vposhSaucer	Saucer
02A9:02AA	vposhSaucerShots	Saucer Shots 2-1
02AB:02AE	vposhShipShots	Ship Shots 4-1

02AF - 02D1 Horizontal Position Low (0-255), 0 = Left, 255 = Right

02AF:02C9	hposlAsteroids	Asteroids 27-1
02CA	hposlShip	Ship
02CB	hposlSaucer	Saucer
02CC:02CD	hposlSaucerShots	Saucer Shots 2-1
02CE:02D1	hposlShipShots	Ship Shots 4-1

02D2 - 02F4 Vertical Position Low (0-255), 0 = Bottom, 255 = Top

02D2:02EC	vposlAsteroids	Asteroids 27-1
02ED	vposlShip	Ship
02EE	vposlSaucer	Saucer
02EF:02F0	vposlSaucerShots	Saucer Shots 2-1
02F1:02F4	vposlShipShots	Ship Shots 4-1
02F5	asteroidsPerWave	Starting Asteroids Per Wave
02F6	curAsteroidCount	Current Amount Of Asteroids
02F7	saucerTimer	Countdown Timer For Saucer, At 0, Saucer Appears. Also Used For Time Between Saucer Shots While Saucer Is Alive
02F8	saucerTimeReload	Starting Value For Timer At 02F7
02F9	asteroid_hit_timer	Goes Up After Explosion
02FA	shipSpawnTimer	Timer For Ship Spawning
02FB	astdWaveTimer	Timer For Asteroid Wave
02FC	astWaveTimerReload	Starting Value For Timer At 6E
02FD	max_rocks_for_ufo	Goes Up By One Every Wave
02FE	$02FE
02FF	$02FF

Holding area for "other player"

0300:03FF	otherPlayerRAM	Other Player RAM