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ros:data_locations:ram_map [2020/04/04 20:15] – created - external edit 127.0.0.1ros:data_locations:ram_map [2025/06/18 11:18] (current) – felixwright
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-======Return of Samus: RAM Map====== +~~REDIRECT>ros:locations:ram~~
-An in-progress RAM map to aid in custom assembly and ROM disassembly. +
- +
-=== Overview === +
-<code> +
-0000-3FFF: 16KB ROM Bank (fixed - bank 0) +
-4000-7FFF: 16KB ROM Bank (swappable) +
-8000-9FFF: 8KB Video RAM +
-A000-BFFF: 8KB Save RAM +
-C000-DFFF: 8KB Work RAM +
-E000-FDFF: Echo RAM (unused) +
-FE00-FE9F: OAM +
-FEA0-FEFF: Not usable +
-FF00-FF7F: I/O Ports +
-FF80-FFFE: High RAM +
-FFFF:      Interrupt enable register +
-</code> +
- +
-=== VRAM === +
-<code> +
-8000-97FF: VRAM tiles +
-    8000-87AF: Samus +
-        8080-9F: Arm cannon +
-    8B00-8EFF: Enemies +
-        0x8C00-8E2F: Characters if room has message box (probably loaded with chozo?) +
-    9000-97FF: Background +
-9800-9FFF: VRAM tilemap +
-    9800-9BFF: Background +
-    9C00-9FFF: Window +
-        9C00: Status bar +
-        9C20: Message +
-</code> +
- +
-=== SRAM === +
-<code> +
-A000-A03F: File 1 +
-    + 00-07: 0123456789ABCDEF +
-    + 08: Samus' Y position +
-    + 0A: Samus' X position +
-    + 0C: Screen Y position +
-    + 0E: Screen X position +
-    + 10: Enemy tiles source address (2 bytes) +
-    + 12: Background tiles source bank +
-    + 13: Background tiles source address (2 bytes) +
-    + 15: Metatile definitions source address (bank 8, 2 bytes) +
-    + 17: Source address of data for $DC00..FF (bank 8, 2 bytes) +
-    + 19: Bank for current room +
-    + 1A: Samus passable block threshold +
-    + 1B: Enemy passable block threshold +
-    + 1C: Projectile passable block threshold +
-    + 1D: Samus' equipment +
-    + 1E: Samus' beam +
-    + 1F: Samus' energy tanks +
-    + 20: Samus' health +
-    + 22: Samus' max missiles +
-    + 24: Samus' missiles +
-    + 26: Direction Samus is facing +
-    + 27: Acid damage +
-    + 28: Spike damage +
-    + 29: Real number of Metroids remaining +
-    + 2A: Song for room +
-    + 2B: In-game timer, minutes +
-    + 2C: In-game timer, hours +
-    + 2D: Number of Metroids remaining +
-A040-A07F: File 2 +
-A080-A0BF: File 3 +
-A0C0:       Last used save slot +
- +
-A800-ACE2: Written to in credits [$6:7920..7E02] +
- +
-B000-B1BF: File 1 Item/Metroid data (0x40 bytes per map) +
- +
-B200-B3BF: File 2 Item/Metroid data (verify) +
- +
-B400-B5BF: File 3 Item/Metroid data +
-</code> +
- +
-=== WRAM === +
-<code> +
-C000-9F: OAM buffer (gets copied by the sprite DMA) +
-    + 0: Y position +
-    + 1: X position +
-    + 2: Tile number +
-    + 3: Attributes +
-         10: Palette +
-         20: X flip +
-         40: Y flip +
-         80: Priority (set: behind background) +
- +
-C203: Tile Y (see $22BC) +
-C204: Tile X (see $22BC) +
-C205: Scroll Y +
-C206: Scroll X +
- +
-C215: Tilemap address of ([$C204], [$C203]) (see $22BC) +
- +
-C308-37: Ch slots of 4 bytes according to $3:6E36 +
-    + 3: XOR'd with 10h in $6E36 every fourth frame +
- +
-C3A1: Scroll X for LCD interrupt handler type = 1 +
- +
-C3A8: X position of Metroid Queen's head on screen +
-C3A9: Y position of Metroid Queen's head on screen +
-C3AA: A two-byte pointer to LCD interrupt data +
- +
-C3D2: Background palette for LCD interrupt handler type = 1 +
-C3D3: Metroid Queen's health +
- +
-C3EF: Set to 1 in $3:6E36 if 0 < [Metroid Queen's health] < 32h, probably an aggression flag +
- +
-C3F1: Set to 1 in $3:6E36 if 0 < [Metroid Queen's health] < 64h, probably an aggression flag +
- +
-C407: Set to [$D069] in $2:4000 +
- +
-C40F: bottom-most visible metatile row index in map * $10 (big-endian word). +
-C411: top-most visible metatile row index in map * $10 (big-endian word). +
-C413: right-most visible metatile column index in map * $10 (big-endian word). +
-C415: left-most visible metatile column index in map * $10 (big-endian word). +
- +
-C417: Number of tile that Baby Metroid is touching. +
-C418: Set to [$D058] in $2:4000 +
- +
-C422: Cleared by $2EE3, set to 1 by $1FF5 +
-C423: Value for $D00F in $2EE3, cleared by $1FF5 +
-C424: Read by $2EE3, set to [$D078] by $1FF5 +
- +
-C430: Used as index for pointer table at $1:5AB1 +
- +
-C432: Scroll Y two frames ago (according to $3:4000) +
-C433: Scroll Y one frame ago (according to $3:4000) +
-C434: Scroll X two frames ago (according to $3:4000) +
-C435: Scroll X one frame ago (according to $3:4000) +
- +
-C44B: Checked and set in $2:4000, previous value for $C458 in $239C +
- +
-C459: Used by $1:7A6C (when saving to SRAM), decides where in C540.. to process for $C900 +
- +
-C45C: Used as index for table at $1:729C, value for $FFEA +
- +
-C500-FE: Object spawn states (map-specific) +
-    C500-C53F: Non-persistent object (e.g. enemy) spawn states +
-        01: Spawned in object table ("visible") +
-        02: Dead/acquired +
-        FF: Not spawned +
-    C540-7F: Persistent object (e.g. item, Metroid) spawn states +
- +
-C600..C7FF: Enemy data. 20h byte slots according to $30BB, current address is kept in $D05E +
-    + 0: Flags. If bits 0-3 clear, $30BB executes $30EA on slot. If bit 7 is set sprite is invisible (blinking). +
-    + 1: Y coordinate. Value for $FFB7 in $30EA +
-    + 2: X coordinate. Value for $FFB8 in $30EA +
-    + 3: Metasprite number. Value for $FFB9 in $30EA +
-    + 4: Priority bit ($80) for sprites. Value for $FFBF in $30EA +
-    + 5: Sprite flip flags ($20 for horizontal, $40 for vertical) +
-    + 6: Low nibble is blink frames remaining. Bit 4 is sprite palette flag. +
-    + A: Frozen frame counter. Increments by 2 every 4 frames. 0 is not frozen, 1-$C4 is frozen, $C5-$D0 is thawing. +
-    + B: Health +
-    + 1D: Map object slot index +
- +
-C900-CABF: Item/Metroid data bytes (0x40 per map, gets saved to SRAM) +
- +
-CEC0-CFFF: Audio data +
-    CEC0: Tone/sweep channel sound effect +
-        CEC0: Tone/sweep channel sound effect to play +
-                0: Nothing +
-                1: Jumping +
-                2: Hi-jumping +
-                3: Screw attacking +
-                4: Uncrouching / turning around / landing +
-                5: Crouching / unmorphing +
-                6: Morphing +
-                7: Shooting beam +
-                8: Shooting missile +
-                9: Shooting ice beam +
-                Ah: Shooting plasma beam +
-                Bh: Shooting spazer beam +
-                Ch: Picked up missile drop +
-                Dh: Spider ball +
-                Eh: Picked up energy drop +
-                Fh: Shot missile door with beam +
-                10h:  +
-                11h:  +
-                12h:  +
-                13h: Bomb laid +
-                14h:  +
-                15h: Option select / missile select +
-                16h: Shooting wave beam +
-                17h:  +
-                18h: Samus' health changed +
-                19h: No missile dud shot +
-                1Ah:  +
-                1Bh: Metroid cry +
-                1Ch: Saved +
-                1Dh:  +
-                1Eh: Unpaused +
-        CEC1: Tone/sweep channel sound effect playing +
- +
-        CEC3: Tone/sweep channel sound effect timer +
-     +
-    CEC7: Tone channel sound effect +
-        CEC7: Tone channel sound effect to play +
-                0: Nothing +
-                1: Nothing +
-                2: Nothing +
-                3: Metroid Queen cry +
-                4: Baby Metroid hatched / clearing blocks +
-                5: Baby Metroid cry +
-                6: Metroid Queen hurt cry +
-                7:  +
-        CEC8: Tone channel sound effect playing +
-         +
-        CECA: Tone channel sound effect timer +
- +
-    CECE-CED4: Would be the wave channel sound effect, but is unused (only cleared) and CEE6 is exclusively used instead. +
- +
-    CED5: Noise channel sound effect +
-        CED5: Noise channel sound effect to play +
-                0: Nothing +
-                1: Enemy shot +
-                2: Enemy killed +
-                3:  +
-                4: Shot block destroyed +
-                5: Metroid hurt +
-                6: Samus hurt +
-                7: Acid damage +
-                8: Shot missile door with missile +
-                9: Metroid Queen cry +
-                Ah: Metroid Queen hurt cry +
-                Bh: Samus killed +
-                Ch: Bomb detonated +
-                Dh: Metroid killed +
-                Eh:  +
-                Fh:  +
-                10h Footsteps +
-                11h:  +
-                12h:  +
-                13h:  +
-                14h:  +
-                15h:  +
-                16h: Baby Metroid hatched / clearing blocks +
-                17h: Baby Metroid cry +
-                18h:  +
-                19h:  +
-                1Ah:  +
-        CED6: Noise channel sound effect playing +
-         +
-        CED8: Noise channel sound effect timer +
- +
-    CEDC: Song to play +
-            0: Nothing +
-            1: Baby Metroid +
-            2: Metroid Queen battle +
-            3: Chozo ruins +
-            4: Main caves +
-            5: Sub caves 1 +
-            6: Sub caves 2 +
-            7: Sub caves 3 +
-            8: Final caves +
-            9: Metroid hive +
-            Ah: Item-get +
-            Bh: Metroid Queen hallway +
-            Ch: Metroid battle +
-            Dh: Sub caves 4 +
-            Eh: Earthquake +
-            Fh: Killed Metroid +
-            10h: Nothing +
-            11h: Title +
-            12h: Samus fanfare +
-            13h: Reach the gunship +
-            14h: Chozo ruins, same as 3 +
-            15h: Main caves, no intro +
-            16h: Sub caves 1, no intro +
-            17h: Sub caves 2, no intro +
-            18h: Sub caves 3, no intro +
-            19h: Final caves, same as 8 +
-            1Ah: Metroid hive, same as 9 +
-            1Bh: Item-get, same as Ah +
-            1Ch: Metroid Queen hallway, same as Bh +
-            1Dh: Metroid battle, same as Ch +
-            1Eh: Sub caves 4, no intro +
-            1Fh: Metroid hive with intro +
-            20h: Missile pickup +
-    CEDD: Song playing +
-    CEDE: Isolated sound effect to play +
-            0: Go to $42EA +
-            1: Go to $432B, play item-get music +
-            3: Go to $4390 (restores some audio state) +
-            5: Go to $4335, play missile pickup music +
-            8: Go to $43FB +
-            Eh: Go to $433F, play earthquake music +
-            FFh: $CEDE = 0, $CEDF = 0, go to $42FA +
-            Otherwise: Go to $42FA +
-    CEDF: Isolated sound effect playing +
-            If [$CEDE] = 0: +
-                2: Go to $43C4 (set by isolated sound effect to play = 3, restores some audio state) +
-                8: Go to $4418 +
-                Otherwise: Go to $42FA +
- +
-    CEE4: Current tone/sweep channel sound effect +
-    CEE5: Current tone channel sound effect +
-    CEE6: Low health beep / wave channel sound effect +
-            0: Samus' health >= 50 +
-            1: Samus' health < 20 +
-            2: Samus' health < 30 +
-            3: Samus' health < 40 +
-            4: Samus' health < 50 +
-    CEE7: Current noise channel sound effect +
- +
-    CF00-60:  +
-        CF00: Music note offset. Set to [$5F30 + ([song to play] - 1) * 2] & ~1 in $48A0 +
-        CF01: Pointer to value for $CF34/$CF36. Set to [$5F30 + ([song to play] - 1) * 2 + 1] in $48A0 +
-        CF03: Working sound channel (1/2/3/4) +
-        CF04: Set to 1 if [$CF38] != 0 in $48A0 +
-        CF05: Set to 2 if [$CF41] != 0 in $48A0 +
-        CF06: Set to 3 if [$CF4A] != 0 in $48A0 +
-        CF07: Set to 4 if [$CF53] != 0 in $48A0 +
-        CF08: Checked to mirror $CF0B/0C to $CF10/11 in $497A +
-        CF09: Pointer to wave pattern data, 10h bytes +
-        CF0B: Working sound channel sweep / enable +
-        CF0C: Working sound channel sound length / wave pattern duty +
-        CF0D: Working sound channel envelope / volume +
-        CF0E: Working sound channel frequency / noise channel polynomial counter +
-        CF0F: Working noise channel counter control +
-        CF10-23: Audio channel options (which conveniently correspond with FF10-23) +
-            CF10: Tone/sweep channel sweep +
-            CF11: Tone/sweep channel sound length / wave pattern duty +
-            CF12: Tone/sweep channel envelope +
-            CF13: Tone/sweep channel frequency +
-            CF15: Unused +
-            CF16: Tone channel sound length / wave pattern duty +
-            CF17: Tone channel envelope +
-            CF18: Tone channel frequency +
-            CF1A: Wave channel enable +
-            CF1B: Wave channel sound length +
-            CF1C: Wave channel volume +
-            CF1D: Wave channel frequency +
-            CF1F: Unused +
-            CF20: Noise channel sound length +
-            CF21: Noise channel envelope +
-            CF22: Noise channel polynomial counter +
-            CF23: Noise channel counter control +
-         +
-        CF26: Song tone/sweep channel instruction pointer +
-        CF28: Song tone channel instruction pointer +
-        CF2A: Song wave channel instruction pointer +
-        CF2C: Song noise channel instruction pointer +
-        CF2E: A 12 frame timer +
-        CF2F-37: Working song sound channel options +
-            CF2F: Instruction pointer +
-                F1 ee ss ll: For non-wave channels. Working sound channel envelope = ee, working sound channel sweep = ss, working sound channel sound length / wave pattern duty = ll +
-                F1 pppp vv:  For the wave channel. Pointer to wave pattern data = pppp, working sound channel volume = vv +
-                F2 pppp:     $CF01 = pppp +
-                F3 oo:       Add oo to any played music notes (sets $CF00) +
-                F4 nn:       Repeat from after this instruction nn times |: (sets $CF31/$CF33) +
-                F5:          Repeat :| (decrements $CF31) +
-            CF31: Repeat count +
-            CF33: Repeat point +
-             +
-            CF35: Sound envelope / volume +
- +
-            CF37: Sound length (according to song instruction F1h) +
-        CF38-40: Song tone/sweep channel options +
-            CF38: Set to [$5F30 + ([song to play] - 1) * 2 + 3] in $48A0 +
-             +
-            CF3F: Set to 1 in $48A0 +
-        CF41-49: Song tone channel options +
-            CF41: Set to [$5F30 + ([song to play] - 1) * 2 + 5] in $48A0 +
-             +
-            CF48: Set to 1 in $48A0 +
-        CF4A-52: Song wave channel options +
-            CF4A: Set to [$5F30 + ([song to play] - 1) * 2 + 7] in $48A0 +
-             +
-            CF51: Set to 1 in $48A0 +
-        CF53-5B: Song noise channel options +
-            CF53: Set to [$5F30 + ([song to play] - 1) * 2 + 9] in $48A0 +
-             +
-            CF5A: Set to 1 in $48A0 +
-        CF5C: Set to D0h by [$CEDE] == 8 (timer), sets $CF3E = $CF47 = $CF59 = $CF5D = $CF5E = [a] +
-            0: Song play = isolated sound effect to play = 0, disable sound channels +
-            10h: a = 13h +
-            30h: a = 25h +
-            70h: a = 45h, $CF07 = 0, $CF50 = $CF5F = 60h +
-            A0h: a = 65h +
-        CF5D: Set to [$CF3E] by [$CEDE] == 8 +
-        CF5E: Set to [$CF47] by [$CEDE] == 8 +
-        CF5F: Set to [$CF50] by [$CEDE] == 8 +
-        CF60: Tone channel frequency tweak. Set to 1 if [$5F30 + ([song to play] - 1) * 2] & 1 in $48A0 +
-    CF61-C1: Mirror of $CF00-60? +
- +
-    CFC5: Backup of song playing during isolated sound effect +
- +
-    CFC7:  +
-            1: Go to $4801 +
-            2: Go to $4846. Set when unpausing: plays unpaused sound effect +
-            Otherwise: $4819 +
-    CFC8: Flag to go to $4852, set to 40h by $4801 +
-    CFC9: Mirror of $CF10? (tone/sweep channel sweep) +
- +
-    CFE3: Mirror of $CF09? +
-    CFE5: Low health beep / wave channel sound effect to play +
-    CFE6: Low health beep / wave channel sound effect playing +
-    CFE7: Mirror of $CFE6? +
- +
-    CFEC: Mirror of $CFED? +
-    CFED: Audio channel output stereo flags +
-    CFEE: Quickly guessing wave pattern timer +
- +
-D008: Metatile top-left +
-D009: Metatile top-right +
-D00A: Metatile bottom-left +
-D00B: Metatile bottom-right +
-D00C: Samus' previous Y position +
-D00E: Door transition direction +
-        1: Right +
-        2: Left +
-        4: Up +
-        8: Down +
-D00F: Direction facing while spin-jumping or morph-jumping. +
-        00: Up +
-        01: Right +
-        FF: Left +
-         +
-D010: Counter for spin-jumping +
-D011: Nothing. Only cleared +
-D012: Value for $D060 in $31F1 +
- +
-D020: Samus' pose +
-        00: Standing +
-        01: Jumping +
-        02: Spin-jumping +
-        03: Running (set to 83h when turning) +
-        04: Crouching +
-        05: Morphball +
-        06: Morphball jumping +
-        07: Falling +
-        08: Morphball falling +
-        09: Starting to jump +
-        0A: Starting to spin-jump +
-        0B: Spider ball rolling +
-        0C: Spider ball falling +
-        0D: Spider ball jumping +
-        0E: Spider ball +
-        0F: Knockback +
-        10: Morphball knockback +
-        11: Standing bombed +
-        12: Morphball bombed +
-        13: Facing screen +
-        18: Being eaten by Metroid Queen +
-        19: In Metroid Queen's mouth +
-        1A: Being swallowed by Metroid Queen +
-        1B: In Metroid Queen's stomach +
-        1C: Escaping Metroid Queen +
-        1D: Escaped Metroid Queen +
- +
-D022: += 3 in $08FE during door transition +
-D023: Direction of screen movement +
-        10: Right +
-        20: Left +
-        40: Up +
-        80: Down +
- +
-D027: Samus X position +
-D029: Samus Y position +
-D02B: Direction Samus is facing, mirrored from $D81E at save load. +
-        0: Left +
-        1: Right +
-D02C: Samus turning animation counter +
- +
-D035: Screen right velocity +
-D036: Screen left velocity +
-D037: Screen up velocity +
-D038: Screen down velocity +
-D039: Set to 0 by load title screen +
- +
-D03B: Samus' Y position on screen +
-D03C: Samus' X position on screen, checked for <= A0h in $08FE +
-D03D: Spider ball direction +
-        0: In air +
-        1: On bottom-left corner of ledge +
-        2: On top-left corner of ledge +
-        3: On left-facing wall +
-        4: On bottom-right corner of ledge +
-        5: On ceiling +
-        6: Unused +
-        7: On meet of left-facing wall and ceiling +
-        8: On top-right corner of ledge +
-        9: Unused +
-        Ah: On floor +
-        Bh: On meet of left-facing wall and floor +
-        Ch: On right-facing wall +
-        Dh: On meet of right-facing wall and ceiling +
-        Eh: On meet of right-facing wall and floor +
- +
-D045: Samus' equipment, mirrored from $D815 at save load. +
-        01: Bombs +
-        02: Hi-jump +
-        04: Screw attack +
-        08: Space jump +
-        10: Spring ball +
-        20: Spider ball +
-        40: Varia suit +
-D046: Debug screen selector index +
-D047: Tiles update flag (see $FFB1..B6, $2BA3, $27BA) +
- +
-D04D: Weapon equipped. +
-        0: Normal +
-        1: Ice +
-        2: Wave +
-        3: Spazer +
-        4: Plasma +
-        8: Missile +
-D04E: Bank +
- +
-D050: Samus' max energy tanks, mirrored from $D817 at save load. +
-D051: Samus' health, mirrored from $D818 at save load. +
-D052: Samus' filled energy tanks, mirrored from $D819 at save load. +
-D053: Samus' missiles(upper nybble tens, lower nybble ones), mirrored from $D81C at save load. +
-D054: Samus' missiles(upper nybble thousands, lower nybble hundreds), mirrored from $D81D at save load. +
-D055: Samus' beam. Saved to SRAM, mirrored from $D816 at save load. +
-        0: Normal +
-        1: Ice +
-        2: Wave +
-        3: Spazer +
-        4: Plasma +
-D056: Samus passable block threshold +
-D057: Room sprite priority +
-        0: Sprites over BG +
-        1: BG over sprites +
-D058: Bank for current room +
-D059: Death sequence timer. Used as index into offset table for dest address in $2FE1 +
- +
-D064: Used in $239C as new OAM stack pointer, set to OAM stack pointer in $04DF +
-D065: VRAM DMA bank (see $FFB1-B6, $2BA3) +
-D066: Used in v-blank handler. Timer for fade in. Set to 40h by $0CA3, set to 2Fh by $239C when type = Ah, set to A0h by game mode Ah, set to FFh by reached the gunship +
-D067: Used in title. Set to 01h by $0CA3 and game mode Ah +
- +
-D069: Enemy passable block threshold +
- +
-D06E: Highest OAM stack pointer +
- +
-D073: Two byte pointer, data for [$C215] before subtracting 21h; pointer to SRAM? Compared with F0h to enable $D09F, probably credits text +
- +
-D076: Used in v-blank handler. Flag to go to $5:403D; set every few frames during credits +
-D077: Acid damage. Saved to SRAM +
-D078: Spike damage. Saved to SRAM +
-D079: Flag to load characters. But also used in facing screen as a flag to check if buttons are pressed +
-D07A: Save slot option selected +
-        0: Start +
-        1: Clear +
-D07B: Used in title. Y position of stars? +
-D07C: Used in title. X position of stars? +
- +
-D07E: BG palette +
-D07F: Object 0 palette +
-D080: Object 1 palette +
-D081: Samus' max missiles(upper nybble tens, lower nybble ones), mirrored from $D81A at save load. +
-D082: Samus' max missiles(upper nybble thousands, lower nybble hundreds), mirrored from $D81B at save load. +
-D083: Read in $1:7A34, adjusts sprite Y position in $1:4DDF +
-D084: Samus' health for display,   mirror of $D051/D818? +
-D086: Samus' missiles for display, mirror of $D053/$D81C? +
- +
-D089: Real number of Metroids remaining +
-D08A: Projectile passable block threshold +
-D08B: Metroid Queen's room flag +
-        11h: In Metroid Queen's room (set by screen transition command 8) +
- +
-D08D: Value for $D05D in $31F1 +
-D08E: Index of screen transition command set. +
-        Set to [$4300 + ([screen Y position high] * 10h + [screen X position high]) * 2] & ~800h by set up door transition +
-D090: Metroid Queen eating pose +
-        Sets Samus pose = escaping Metroid Queen when 7, checked for 5/20h and set to 6 in in Metroid Queen's mouth +
-        0: Otherwise +
-        1: Samus entering mouth +
-        2: Mouth closing +
-        3: Mouth closed +
-        5: Samus escaping mouth +
-        6: Swallowing Samus +
-        7:  +
-        8: Samus escaping stomach +
-        10h: Paralysed (can enter mouth) +
-        20h:  +
-        22h: Dying +
-D091: Set to 3 in $8:7EBC if killed a target number of Metroids or 1 if only Metroid Queen is remaining +
-D092: Song for room +
- +
-D096: Metroids remaining shuffle timer +
-D097: Index for $5:5620 jump table (first call in credits) +
-D098: In-game timer, minutes +
-D099: In-game timer, hours +
-D09A: Number of Metroids remaining +
-D09B: Fade in timer +
- +
-D09E: Checked and cleared in $2:4000, value for $FFC9 in $0C37 +
-D09F: Flag to display in-game time in credits +
-D0A0: Debug flag +
- +
-D0A2: In-game timer, 256-frame periods (roughly 14ths of a minute) +
-D0A3: Save slot +
-D0A4: Show clear save slot option flag +
- +
-D0A7: Metroids remaining in area +
- +
-D600-1F: OAM data for the starry background in the credits. +
- +
-D700-3F: Screen transition commands +
- +
-D800-25: Save data. Data loaded from $1:4E64-89 by game mode Bh, loaded from $A008-2D + save slot * 40h by game mode Ch +
-    D800: Samus' Y position +
-    D802: Samus' X position +
-    D804: Screen Y position +
-    D806: Screen X position +
-    D808: Enemy tiles source address (2 bytes) +
-    D80A: Background tiles source bank +
-    D80B: Background tiles source address (2 bytes) +
-    D80D: Metatile definitions source address (bank 8, 2 bytes) +
-    D80F: Source address of data for $DC00-FF (bank 8, 2 bytes) +
-    D811: Bank for current room +
-    D812: Samus passable block threshold (>= this tile index is passable, < is impassible) +
-    D813: Enemy passable block threshold +
-    D814: Projectile passable block threshold +
-    D815: Samus' equipment at save load. +
-    D816: Samus' beam at save load. +
-    D817: Samus' max energy tanks at save load. +
-    D818: Samus' health at save load. +
-    D819: Samus' filled energy tanks at save load. +
-    D81A: Samus' max missiles at save load. Upper nybble tens, lower nybble ones. +
-    D81B: Samus' max missiles at save load. Upper nybble thousands, lower nybble hundreds. +
-    D81C: Samus' missiles at save load. Upper nybble tens, lower nybble ones. +
-    D81D: Samus' missiles at save load. Upper nybble thousands, lower nybble hundreds. +
-    D81E: Direction Samus is facing at save load. +
-    D81F: Acid damage +
-    D820: Spike damage +
-    D821: Real number of Metroids remaining +
-    D822: Song for room +
-    D823: In-game timer, minutes +
-    D824: In-game timer, hours +
-    D825: Number of Metroids remaining +
- +
-D900-FF: 10h byte slots? The first byte of which each is cleared when saving +
-DA00-DBFF: Metatile definitions +
-DC00-FF: Tile properties +
-    1: Viscous. Reduces jumping and detaches spider ball on movement. Also causes morph ball sound effect glitch. +
-    2: Jump-through block. Passable when jumping, impassable in all other states (in all directions). +
-    4: Fall-through block. Passable when falling, impassable in all other states (in all directions). +
-    8: Spike +
-    10h: Acid +
-    20h: Destructible by shot/bomb +
-    40h: Destructible by bomb +
-    80h: Save pillar +
- +
-DD00-FF: Projectile RAM +
-    Beams - Takes up three 16-byte rows for each shot on-screen. Spazer and Plasma take up all three immediately. +
-    DD00, DD10, DD20: Beam state. +
-        0-4: On-screen, being fired. Value will match the currently-equipped beam's as stored at D055. +
-        FFh: Not on-screen. +
-    DD01, DD11, DD21: Direction of fire. +
-        1: To the right. +
-        2: to the left. +
-        4: Upwards. +
-        8: Downwards. +
-    DD02, DD12, DD22: Shot Y position. +
-    DD03, DD13, DD23: Shot X position. +
-    DD04, DD14, DD24: Unknown, switches between 0 and 8 on a seemingly random interval between firings. +
-    DD05, DD15, DD25: Displacement from position fired at, ends up differently for each direction. +
-     +
-    Missiles - Shares a 16-byte row with the third beam slot. +
-    DD20: Missile state. +
-        8: On-screen, being fired. +
-        FFh: Not on-screen. +
-    DD21: Direction of fire. +
-        1: To the right. +
-        2: to the left. +
-        4: Upwards. +
-        8: Downwards. +
-    DD22: Shot Y position. +
-    DD23: Shot X position. +
-    DD24: Unknown, switches between 0 and 8 on a seemingly random interval between firings. +
-    DD25: Displacement from position fired at, ends up differently for each direction. +
-     +
-    Bombs - Takes up three 16-byte rows for each bomb on-screen. +
-    DD30, DD40, DD50: Bomb state. +
-        1: Laid, waiting to explode. +
-        2: Exploding. +
-        FFh: No bomb on-screen. +
-    DD31, DD41, DD51: Bomb timer. Starts at the value it was set at and decreases to zero. +
-    DD32, DD42, DD52: Bomb Y position. +
-    DD33, DD43, DD53: Bomb X position. +
-     +
-DE00-FF: Metatile update entries +
-    + 0: Dest. address. $0000 terminates update +
-    + 2: Top-left tile +
-    + 3: Top-right tile +
-    + 4: Bottom-left tile +
-    + 5: Bottom-right tile +
-DF00-FF: Stack +
-</code> +
- +
-=== HRAM === +
-<code> +
-FF80: Buttons +
-        01: A +
-        02: B +
-        04: Select +
-        08: Start +
-        10: Right +
-        20: Left +
-        40: Up +
-        80: Down +
-FF81: New buttons +
-FF82: V-blank handled flag +
- +
-FF8D: OAM stack pointer +
- +
-FF97: Frame counter +
-FF98: Sprite tile number (see $5:4015). Mirror of sprite Y position (see $30BB). Door scroll flags (see $08FE): [$4200 + [screen Y position, screen] * 16 + [screen X position, screen]] +
-FF99: Two sprite tile numbers (see $5:4000). Mirror of sprite X position (see $30BB). Door thing (see $08FE): [Samus' Y position] - [$FFC8] + 60h +
- +
-FF9B: Game mode +
-        0: Boot +
-        1: Title screen +
-        2: Loading save 2 +
-        3: Loading save 3 +
-        4: In-game +
-        5: Dead +
-        6: Dying +
-        7: Game over +
-        8: Paused +
-        9: Save to SRAM +
-        Ah: Unused +
-        Bh: Start new game +
-        Ch: Load from save +
-        Dh: RET +
-        Eh: RET +
-        Fh: Unused. Identical to 7, set by game mode Ah +
-        10h: Unused. Game cleared +
-        11h: Unused. Functionally identical to 7, set by game mode 10h +
-        12h: Reached the gunship +
-        13h: Credits +
- +
-FFA0-A9: OAM DMA routine +
-FFAA: VRAM tilemap metatile update address. $FFAA = $9800 + ([row block to update] * 32 + [column block to update]) * 2 +
-FFAC: Index of screen for metatile update. $FFAC = [row screen to update] * 16 + [column screen to update] +
-FFAD: Index of block for metatile update. $FFAD = [row block to update] * 16 + [column block to update] +
-FFAE: Number of blocks to update +
-FFAF: Stack pointer for metatile update entries +
-FFB1: VRAM DMA source address +
-FFB3: VRAM DMA dest address, also source offset from $CE20 when [$D08C] is set +
-FFB5: VRAM DMA size +
-FFB7-BB: Energy tank graphics, other stuff too though +
-FFB7: Offset for interval for [$FF98] in $30EA +
-FFB8: Offset for interval for [$FF99] in $30EA +
-FFB9: Table index for offset data     in $30EA +
-FFBA: Start   of interval for [$FF98] in $30EA +
-FFBB: End     of interval for [$FF98] in $30EA +
-FFBC: Start   of interval for [$FF99] in $30EA +
-FFBD: End     of interval for [$FF99] in $30EA +
- +
-FFBF: Flags to negate values in $30EA +
-FFC0: Samus' Y position +
-FFC2: Samus' X position +
-FFC4: Sprite Y position (see $5:4015) +
-FFC5: Sprite X position (see $5:4015) +
-FFC6: Sprite set +
-FFC7: Sprite attributes (see $5:4015) +
-FFC8: Screen Y position +
-FFCA: Screen X position +
-FFCC: Row to update    (in pixels) +
-FFCE: Column to update (in pixels) +
- +
-FFE0-FFF5: Used by active enemies (??) +
- +
-FFFE: Counts every other in-game frame +
-</code> +
ros/data_locations/ram_map.txt · Last modified: by felixwright