Arcana/RAM map

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.
    • item ID / "Equipped by" flag
  • "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
• $13A3: Temp EXP
• $13A5: Temp GP
• $13A7: Spirits not owned (Bit flags: xxxx EMDS) (Example: 6 -> 0110 -> missing Marid/Dao)
• $13A9: Card inventory (Two bytes each, eight entries)
  • (item ID / quantity)
• $13B9: Item inventory (Two bytes each, 48 entries)
  • (item ID / quantity)
• $1419: Equipment inventory (Two bytes each, 48 entries)
  • (item ID / quantity)
• $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