Arcana/RAM map

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Chip tiny.png The following article is a RAM map for Arcana.

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The list corresponds to RAM variables used by the game engine. They are generally accessed by LDA and STA instructions.

Main Loop

  • $1049: Pointer to indirect function calls (JMP [$1049])
  • $1E10: Event pointer, used for reading most of the game's code (LDA [$10]) (long ptr)
  • $1E14: Event pointer stack, stores return addresses during function calls

Temporary Arrays

Typically these are accessed i.e. LDA $09C7,x where the x register is determined at runtime.

  • $0643-065B: Enemies in battle (Enemy ID + 18), set to FFFF when killed
  • $09A3-09BB: ??
  • $09C7-09DF: Miscellaneous return values (i.e. type of treasure contents, item/spell/enemy chosen)
  • $09EB-0A03: Current selection (Attacker ID, caster ID, whose turn is it etc)
  • $0A0F-0A27: Target (ID being attacked, treasure chest being opened)
  • $0B9F,x: Stores function results (0=failure)
  • $0CB3,x: Stores function results (0=failure)

Battle

  • $0A87-$0A8E: Current selected battle command (2 bytes per character)
    • #$0001: Main menu
    • #$0003: Items/Magic
    • #$0004: Cards
    • #$0005: Weapons
    • #$0008: Attack
  • $1121: Attacker
  • $1123: Target
  • $1127: Spell ID
  • $11C1: Battle state (00=not fighting/can move, 02=battle poses, )
  • $11C3: Status/Condition (a series of words in the order: Rooks, Spirit, Guest1, Guest2, Enemies 1-8)
    • Odd byte:
      • #$00: Satisfactory
      • #$01: Deceased
      • #$02: Not Here
      • #$03: Paralyzed
      • #$04: Petrified
      • #$05: Confused
      • #$06: Sleeping
    • Even byte: #$01 indicates a party member
  • $11F3-11FA: Order that spells hit the party (2 bytes per character)
    • #$0000: Upper left
    • #$0001: Upper right
    • #$0002: Lower left
    • #$0003: Lower right
  • $120B: Rooks' Element/Race
  • $120D: Spirit's Element/Race
  • $120F: Guest1's Element/Race
  • $1212: Guest2's Element/Race
  • $1214: Enemy1's Element/Race
    • Bytes continue with Enemy2-8 in order
  • $1223: Rooks' Strength
  • $1225: Spirit's Strength
  • $1227: Guest1's Strength
  • $1229: Guest2's Strength
  • $122B: Enemy1's Strength (table offset?)
    • Bytes continue with Enemy2-8 in order
  • $123B: Rooks' Intelligence (reduces magic damage taken)
  • $123D: Spirit's Intelligence
  • $123F: Guest1's Intelligence
  • $1241: Guest2's Intelligence
  • $1243: Monsters' Intelligence (affects spell damage)
    • Bytes continue with Enemy2-8 in order
  • $1253: Rooks' Endurance (reduces physical damage taken)
  • $1255: Spirit's Endurance
  • $1257: Guest1's Endurance
  • $1259: Guest2's Endurance
  • $125B: Enemy1's Endurance
    • Bytes continue with Enemy2-8 in order
  • $126B: Rooks' Alertness (affects accuracy, evasion and critical hits)
  • $126D: Spirit's Alertness
  • $126F: Guest1's Alertness
  • $1271: Guest2's Alertness
  • $1273: Enemy1's Alertness
    • Bytes continue with Enemy2-8 in order
  • $1283: Equipped weapons
    • Two bytes each, in order of Rooks, Guest 1 and Guest 2.
    • "Equipped by" flags:
      • #$00: Rooks
      • #$05: Teefa
      • #$06: Salah
      • #$07: Darwin
      • #$08: Axs
  • $129B: Equipped armors
  • $12B3: Equipped shields/accessories
  • $12CB: Equipped rings
  • $12E3: Accuracy modifier (concerns Acc. Increase All and Accuracy Impair)
    • There are 3 possible states: StatDown, Normal and StatUp. StatUp and StatDown cancel each other out.
    • Byte values are as follows:
      • #$01: Rooks' accuracy up
      • #$04: Spirit's accuracy up
      • #$10: Guest1's accuracy up
      • #$40: Guest2's accuracy up
      • #$02: Rooks' accuracy down
      • #$08: Spirit's accuracy down
      • #$20: Guest1's accuracy down
      • #$80: Guest2's accuracy down
  • $12E5: Accuracy modifier (enemies)
  • $12E7: Evasion modifier (concerns Dodge All and Offense Impair) (same flags)
  • $12E9: Evasion modifier (enemies)
  • $12EB: Attack modifier (concerns Stomp All and Attack Impair) (same flags)
  • $12ED: Attack modifier (enemies)
  • $12EF: Defense modifier (concerns Wall All and Defense Impair) (same flags)
  • $12F1: Defense modifier (enemies)
  • $12F3: HP, Rooks
  • $12F5: HP, Spirit
  • $12F7: HP, Guest1
  • $12F9: HP, Guest2
  • $12FB: HP, Enemy1
    • Bytes continue with Enemy2-8 in order
  • $1323: MP, Rooks
  • $1325: MP, Spirit
  • $1327: MP, Guest1
  • $1329: MP, Guest2
  • $132B: MP, Enemy1
    • Bytes continue with Enemy2-8 in order
  • $1393: Max HP, Rooks
  • $1395: Max HP, Spirit
  • $1397: Max HP, Guest1
  • $1399: Max HP, Guest2
    • (Next byte is Rooks' Max HP -> Enemies have no max HP/MP stat)
  • $139B: Max MP, Rooks
  • $139D: Max MP, Spirit
  • $139F: Max MP, Guest1
  • $13A1: Max MP, Guest2
  • $13A9: Card inventory (Two bytes each, eight entries)
  • $13B9: Item inventory (Two bytes each, 48 entries)
  • $1419: Equipment inventory (Two bytes each, 48 entries)
  • $1459: Rooks' spell list (Two bytes each, 32 entries)
  • $1499: Spirit's spell list (Two bytes each, 32 entries?)
  • $14D9: Guest1's spell list (Two bytes each, 32 entries?)
  • $1519: Guest2's spell list (Two bytes each, 32 entries?)
  • $1559: Current GP
  • $155B: Current party (Two bytes each)
    • #$00: Rooks
    • #$01: Sylph
    • #$02: Marid
    • #$03: Dao
    • #$04: Efrite
    • #$05: Teefa
    • #$06: Salah
    • #$07: Darwin
    • #$08: Axs
    • #$09: (Empty slot)

Inventory

  • $13A9-$13B7: Card inventory (2 bytes per slot, ID then quantity)
    • #$00: Empty slot
    • #$01: Wind Card
    • #$02: Earth Card
    • #$03: Water Card
    • #$04: Fire Card
    • #$05: Null Card
    • #$06: Fog Card
    • #$07: Call Amulet
    • #$08: Mirror Card (bugged)
  • $13B9-$1418: Item inventory (2 bytes per slot, $30 slots: ID then #$00)
    • #$01: Return Ring
    • #$02: Water of Life (dummied)
    • #$03: Sleeping Bag
    • #$04: Tent
    • #$05: Strength Honey
    • #$06: Intelligence Honey
    • #$07: Endurance Honey
    • #$08: Agility Honey
    • #$09: Restore Honey
    • #$0A: MP Honey
    • #$0B: Herbs
    • #$0C: Medicine
    • #$0D: Silver Flask
    • #$0E: Gold Flask
    • #$0F: Maiden's Tears
    • #$10: Moon Oil
    • #$11: Enchanted Jewel (dummied)
  • $1419–1458: Equipment inventory (2 bytes per slot, $20 slots: ID then Equipped By)
    • Equipped by flags:
    • #$00: Rooks
    • #$05: Teefa
    • #$06: Salah
    • #$07: Darwin
    • #$08: Axs
    • #$FF: Nobody

Actors Continued

  • $1459–$1398: Rooks' spell list (2 bytes per entry, Spell ID followed by #$00)
  • $1499–14D8: Spirit's spell list
  • $14D9-1518: Guest1's spell list
  • $1519–1558: Guest2's spell list
  • $155D: Active spirit
    • $01: Sylph
    • $02: Dao
    • $03: Marid
    • $04: Efrite
    • $09: none
  • $155F: Guest1
  • $1561: Guest2
    • $05: Teefa
    • $06: Salah
    • $07: Darwin
    • $08: Axs
    • $09: none

Miscellaneous

  • $0624-$0626: Active spirit's HP (Format: BCD)
  • $062D: Offset*2 used with $11F3
  • $06F9: X position of cursor
  • $071D: Y position of cursor
  • $09CB: Turn status (02: not turning, 00: turning left, 01: turning right)
  • $0A7F: Compass heading (00: N, 02: NE, 04: E, 06: SE... 0E: NW) (Tracks diagonals unlike $16FB)
  • $105A: Caches which H-DMA channels to run
  • $1064: Current music
  • $1066: Current sfx
  • $10EB-C: ASCII values for number being displayed
  • $1123: Used for asm x offsets
  • $11B5: Tracks progress in intro crawl
  • $11B9: Current page# in item list
  • $1573: ?? (Checked before changing music)
  • $1577: Window color (Bit depth: 0BBB B0GG GG0R RRR0)
  • $1579: Encounter related
  • $157B: Graphics related
  • $1580–16DF: Current display buffer
    • For spells, names are preceded by 06 0D (white) if usable and 06 0E (grayed) if not.
  • $16DB: Temp var (Attack power, battle damage, )
  • $16DD: Temp var (Defense power)
  • $16F3: #$01 if in motion, #$00 if standing still
  • $16F5: Current floor tile value
  • $16F7: Dungeon X position
  • $16F9: Dungeon Y position
  • $16FB: Current direction (#$00 North, #$02 East, #$04 South, #$06 West)
  • $16FD: Related to random encounters (usually 0)
  • $16FF: Map progress
  • $17BF: Map progress (mirror)
  • $1885: Shop selection (i.e. Card shop uses values 0-6)
  • $1895: Torn spirits (4 entries, 2b each: Sylph = 2)
  • $18C5: Spell type
  • $18C9: Temp MP
  • $18CD: Current Chapter # (01-05)
  • $18CF: Weather fx (Used in the intro)
  • $18D5: Stage select counter (adds 2 for every correct button press until $1C)
  • $18D7: Encounter layout (long ptr)
  • $18DA: Encounter enemy list (long ptr)
  • $18DF: Bosses defeated? (0=Ch2 start, 1=Cyclops killed)
  • $18E1: Temp var for Boss encounter (6 = Cyclops)
  • $18E3-$18E8: Treasure chest flags (each chest has its own bit)
  • $18F3: Decompression entry (long ptr)
  • $18F8: Decompression start (long ptr)
  • $18FF: Event pointer
    • 05: Started Chapter 2
    • 0A: Started Chapter 3
    • 0E: Started Chapter 4
    • 18: Started Chapter 5