Super Mario Bros.: The Lost Levels (doppelganger's SMB2J disassembly, threecreepio/smb2j-disassembly)

The Lost Levels keeps Super Mario Bros.'s movement tables for Mario byte for byte. Take-off speeds, held and falling gravities, frictions, and top speeds all match. smb2j/mario-tables

About: Super Mario Bros.: The Lost Levels Jump

Cited by: Super Mario Bros.: The Lost Levels

Picking Luigi copies his own gravities and frictions over Mario's: held gravity $18–$22 for the five jump rows against Mario's $1E–$28, falling gravity $3E–$5D against $60–$90, and friction $B4, $68, $A0 against $E4, $98, $D0. It also writes an RTS over the ASL that doubles Mario's friction when he faces away from his motion. His take-off speeds are Mario's. Each area's setup loads the chosen player's set; the axe at the end of a castle loads Mario's set and ASL back for the walk that follows, whoever is playing, until the next area loads the player's own again. smb2j/luigi-physics

About: Super Mario Bros.: The Lost Levels Jump

{
 "heldGravity": [
  24,
  24,
  24,
  34,
  34
 ],
 "fallGravity": [
  66,
  66,
  62,
  93,
  93
 ],
 "friction": [
  180,
  104,
  160
 ]
}

Cited by: Super Mario Bros. 2, Super Mario Bros.: The Lost Levels

ProcJumping starts a jump only while Player_State is 0, on the ground, or while the player is swimming, as Super Mario Bros.'s does. Walking off a ledge doesn't keep that state: PlayerBGCollision sets a player in the normal or climbing state to falling (or, swimming, to state 1) on each frame of play before it looks for ground, and only landing on a block sets the state back to 0, so out of water a jump can't start after walking off a ledge. The background check skips that step only during the game's scripted routines (GameEngineSubroutine 0 to 3 and $0B). smb2j/no-coyote-time

About: Super Mario Bros.: The Lost Levels Coyote time

Cited by: Coyote time, Super Mario Bros.: The Lost Levels

A hit on big Mario sets InjuryTimer to 8, as in Super Mario Bros., and the timer counts down once every 21 frames with the interval timers, through the same timer loop as Super Mario Bros.'s. smb2j/injury-timer

About: Super Mario Bros.: The Lost Levels Invincibility frames

{
 "ticks": 8,
 "framesPerTick": 21
}

Cited by: Super Mario Bros.: The Lost Levels

Wind blows the player to the right. An area object turns it on (WindOn) and another off (WindOff), and the setup that runs at the start of every area clears it. While it is on, and only in ground-type areas (underground, water, and castle areas stay calm), it moves the player 1 px right on every fourth frame while the frame counter is below 128 and on every second frame from 128 to 255: 96 px every 256 frames, 0.375 px a frame on average. The push is added to the position after the player's own move, on the ground and in the air but not while climbing, so it adds to a rightward speed and takes from a leftward one whatever the speed, and the screen scrolls with it. Its leaves and sound play while it is on, in every type of area. None of it runs until the game has loaded a disk file beyond worlds 1 to 4 (worlds 5 to 8, the ending, or worlds A to D): before that, FileListNumber is 0 and both calls are skipped. smb2j/wind

About: Super Mario Bros.: The Lost Levels Wind

{
 "push": 1,
 "everyFrames": [
  4,
  2
 ],
 "per256Frames": 96,
 "average": 0.375
}

ASL of FrameCounter puts its bit 7 in the carry, so the mask is 1 (every second frame) while the counter is 128-255 and 3 (every fourth) while it is 0-127; the disassembly's comment ("set d0 if on an odd frame") misreads it. SM2DATA2 (worlds 5 to 8) and SM2DATA4 (worlds A to D) each carry the routine (the ROM map's regions blow-player-around and blow-player-around-2). Which areas place WindOn is level data, not read here.

Cited by: Super Mario Bros.: The Lost Levels

A poison mushroom comes out of a block of its own kind, and stays a poison mushroom whatever the player's size, where an ordinary mushroom block gives a fire flower to a big or fiery player. It slides along like a mushroom. Touching it removes it and runs the injury routine: a small player dies, and a big or fiery one drops straight to small, with the blink that follows any hit. During that blink, or while a star's invincibility lasts, it is removed and does nothing. smb2j/poison-mushroom

About: Super Mario Bros.: The Lost Levels Power-up

Power-up type 4. ForceInjury stores A, which is 0 after the timer check falls through, as the player's status, so fiery goes to small in one step. The metatile tables label poison-mushroom versions of the ? block, the hidden block, and two bricks (sm2main.asm lines 2149, 2155, 2162, 2197); which blocks hold one is level data. Super Mario Bros.'s InjurePlayer checks only the blink timer (super-mario-code-lineage/smb1-smb2j-collisions).

Cited by: Super Mario Bros.: The Lost Levels

The poison mushroom is drawn from the same four tiles as the mushroom and the 1-up mushroom ($D8, $DA, $DB, $FF) in sprite palette 3, where the mushroom uses palette 2 and the 1-up palette 1. Like them it keeps its colors, where the fire flower and the star cycle theirs. smb2j/poison-mushroom-look

About: Super Mario Bros.: The Lost Levels Power-up

Which colors palette 3 holds in each kind of area isn't read here.

Cited by: Super Mario Bros.: The Lost Levels

Every area from World 4-4 on, and every area of worlds A to D, starts with the secondary hard mode flag set; the areas of worlds 1 to 3 and 4-1 to 4-3 start without it. The memory clear at the start of each area resets it first. smb2j/hard-mode-from-4-4

About: Super Mario Bros.: The Lost Levels Difficulty ramp

SecondaryHardMode is $06CC, under the $074B limit of the clear. World numbers 4 and up (worlds 5 to 9) branch straight to the set.

Cited by: Super Mario Bros.: The Lost Levels

With the secondary hard mode flag set: enemies the level data marks for hard mode appear, where otherwise they are skipped; a Bullet Bill cannon is picked to fire when a pseudorandom number masked to three bits is below 6 (6 of 8 values, against 6 of 16 with four bits); up to four flying Cheep Cheeps at once instead of three; hammer bros throw on a shorter timer ($1C against $30), can take the longer of two jump timers ($37 against $20), and in worlds 1 to 6 wait a shorter time before walking left ($50 against $80; in worlds 7 to 9 they don't wait either way, and worlds A to D, which share world numbers 1 to 4 and always have the flag, take $50); Bloopers pick a new direction when two pseudorandom bits are clear rather than six, and then a Blooper in an even enemy slot turns toward the player, one in an odd slot takes the player's moving direction; Bowser's fire breath and the flames that fly in on their own come 16 timer ticks sooner, and the flames move faster ($60 subtracted from their fractional position each frame, against $40); and the large lifts are drawn four sprites wide instead of six with a smaller box, as they always are in castles, with balance platforms and their ropes placed for the shorter width. smb2j/hard-mode-effects

About: Super Mario Bros.: The Lost Levels Difficulty ramp

The hammer bro's jump-timer pick is the pseudorandom bits masked with $00, which the code before it sets to 1 only while the hammer bro is above the middle of the screen (Y below $70), so the longer timer comes only up there. Without the flag, balance platforms move 8 px left (PlatPosDataLow's $F8) and their rope 16 px further right. Which enemies carry the hard-mode bit is level data, not read here.

Cited by: Super Mario Bros.: The Lost Levels

The code keeps the primary hard mode flag's checks, which turn Goombas into Buzzy Beetles, start walking enemies faster ($F4 against $F8), and revive stomped enemies sooner and send them off faster. Nothing in The Lost Levels' code sets the flag, and starting a game clears it, so none of these takes effect. Super Mario Bros. sets it from its world select flag when a game starts. smb2j/primary-hard-mode-unset

About: Super Mario Bros.: The Lost Levels Difficulty ramp

PrimaryHardMode is $076A. A search of sm2main.asm, sm2data2-4.asm and fdswrap.asm finds it only as a source (LDA, LDY) and no store to it by name or by its address; InitializeGame's InitializeMemory call clears $0000-$076F (the stack's $0100-$0108 and $0160-$01FF spared), and the cold boot clears more.

Cited by: Super Mario Bros.: The Lost Levels

A warp zone leads to one world, whichever of its pipes the player takes. In world 1 it leads to world 2 from the first underground area, to world 3 from a ground area, and to world 4 from any other; in world 3, back to world 1; in world 5, to world 6 from one ground area (the 12th in the area table, which the disassembly's comment places at 5-1), to world 8 from any other ground area, and to world 7 from any other area; in worlds 2, 4, and 6 to 9, to world 5, which from 6 to 8 is back. In worlds A to D it goes by level: from a second level to world B, a third to world C, a fourth to world D; the table holds no world for a first level. smb2j/warp-destinations

The low nybble of WarpZoneControl indexes WarpZoneNumbers ($02, $03, $04, $01, $06, $07, $08, $05, $0B, $0C, $0D); in worlds A to D the entry less 9 is the letter world's number, so $87 plus level 0 gives $05 - 9, no world. Which areas hold warp zones is level data, not read here.

Cited by: Super Mario Bros.: The Lost Levels

Clearing a world's castle sets that world's bit in a record of completed worlds. After the ending that follows 8-4, the game goes on to World 9 if all eight bits are set, and back to the title screen if any is missing; after D-4 it always goes back to the title. The record is cleared when a game starts and when the player picks Retry at a game over, and Continue keeps it, so a world skipped by a warp counts only if the player warps back and clears its castle. smb2j/world-9-condition

Cited by: Super Mario Bros.: The Lost Levels

World 9 begins with one life. A game over there ends the game, with no continue menu. Its four levels loop: after 9-4 the game starts 9-1 again. smb2j/world-9-rules

The lives counter holds lives less one, as Continue's "ldy

Cited by: Super Mario Bros.: The Lost Levels

Each time the ending loads, after 8-4 or D-4, the count of games beaten goes up by one, to at most 24 (a short read of the ending's files resets it to 0 first). After 8-4 the game writes the count to the disk's save file (a disk error aside); after D-4 it doesn't, and the title screen, which reloads the disk's first files after a game in worlds A to D or from world 5 on, reads the saved count back, so D-4 adds nothing. The title screen shows a star for each game beaten, in two rows of 12. With 8 or more, holding A while pressing Start begins the game at World A, loading worlds A to D, with their own halfway points, from the disk. smb2j/letter-worlds

The count is GamesBeatenCount, the byte that the save file SM2SAVE loads over at $D29F (sm2main.asm line 15279: "this is overwritten by the contents of SM2SAVE"). D-4 reaches the ending because SetupVictoryMode sets the world number to 8 on world D. After D-4, RunMushroomRetainers skips the disk task list that writes the save, and LoadWorlds1Thru4, with HardWorldFlag still set, reloads file list 0 (SM2MAIN, SM2CHAR1, SM2SAVE). A disk error is handled by DiskErrorHandler, not read here.

Cited by: Super Mario Bros.: The Lost Levels

Landing on a springboard sets both the held and the falling gravity to $70 and a launch speed of −7 px a frame ($F9). Over the spring's four steps it carries the player down 2 px a step, then up 2 px a step, and on the last step it launches them. A press of A, not held from before, in the second step or later raises the launch to −12 px a frame ($F4), or to −32 px a frame ($E0) on the green springboards of world numbers 2, 3, and 7, which the letter worlds share as B and C, since the test reads the world number without the letter-world flag. With both gravities at $70, the bounce rises and falls under one pull whether A is held or not, for Mario and Luigi alike. While the game's timers are stopped the spring waits. smb2j/springboard

About: Super Mario Bros.: The Lost Levels Springboard

{
 "gravity": 112,
 "launch": -7,
 "pressed": -12,
 "green": -32
}

The step is JumpspringAnimCtrl, 1 to 4; the handler reads it less one (0 to 3). The player's vertical move is skipped while the spring animates, and its gravity code caps only the fall (ImposeGravitySprObj passes no upward limit). Worlds A to D use world numbers 0 to 3 (the comment at sm2main.asm line 1199).

Cited by: Super Mario Bros.: The Lost Levels

Piranha plants are green in worlds 1 to 3 and red in worlds 4 to 9 and A to D. A green one stays in its pipe while the player is less than 33 px from it across, and moves on every second frame; a red one stays in only while the player is less than 19 px away, and moves on every frame. smb2j/piranha-plants

InitPiranhaPlant patches the operand of the cmp #$21 at ChkPlayerNearPipe+3: $13 for red, $21 for green. The palette patch is in EnemyAttributeData, which RiseFallPiranhaPlant reads back to tell red from green.

Cited by: Super Mario Bros.: The Lost Levels

While Lakitu's stretch of a level runs, the game checks every 128 frames whether a Lakitu is on screen. When none is, it counts the check, and on the third it sends a new Lakitu if an enemy slot is free (if none is, it tries again at the next check); the count starts over when a Lakitu is set up. The new one flies high in worlds 1 to 6 ($20) and lower in worlds 7 to 9 and A to D ($60). When one is on screen, the same check leads to the Spiny throw, not covered here. smb2j/lakitu-return

About: Super Mario Bros.: The Lost Levels Enemy spawning

FrenzyEnemyTimer is $078F, one of the frame timers ($0780-$0794) that count down every frame while the game's timers run.

Cited by: Super Mario Bros.: The Lost Levels

At a game over outside World 9, Select switches between CONTINUE and RETRY and Start picks. Continue restarts the current world at its first level, small, with three lives, the score and coins at zero, and the hidden 1-up available again. Retry ends the game and clears the record of completed worlds. smb2j/continue-or-retry

About: Super Mario Bros.: The Lost Levels Continue

Cited by: Super Mario Bros.: The Lost Levels

Grabbing the flagpole gives an extra life in place of the height's points when the coin count's two digits are the same and match the timer's last digit (11 coins with the timer ending in 1, for example). smb2j/flagpole-1up

About: Super Mario Bros.: The Lost Levels Extra life

Cited by: Super Mario Bros.: The Lost Levels

Fireworks go off over the castle when the timer's last digit matches the coin count's last digit as the level ends: three when the digit is odd, six when it is even, and none when they differ. smb2j/fireworks

Cited by: Super Mario Bros.: The Lost Levels