Mother2GbaTranslation/notes/m2-notes.txt

General notes
=============

Font palette:
- Standard text windows:     0x4 = background, 0xF = foreground
- File select/setup windows: 0x1 = background, 0x9 = foreground

Hard-coded characters:
- 0xFD: bullet (tile 0x1DD)
- 0xFE: equip (tile 0x1DE)
- Null (tile 0x1DF)
- Background (tile 0x1FF)
- 0xB4 - 0xBC: YOU WON! (tile 0x154)

English names:
- Ness: 7E 95 A3 A3
- Pala: 80 91 9C 91
- Jeff: 7A 95 96 96
- Poo:  80 9F 9F

0x2020C70: enemy data slots in-battle? separated by 0x94 bytes
0x2025038: enemy count (initial, not current)
0x20251D8: item drop
0x3000A00: Current PSI list when displaying a PSI window?
0x3000AA0: currently selected party member e.g. when in the Goods windows (-1 if nobody selected)
0x3000AA2: number of party members
0x3001300: number to be printed (e.g. withdrawn money amount)
0x300130C: window flags?
           - 0x0800 is set when any of the A-menu sub-windows are open (Goods, PSI, etc.)
           - 0x0001 is set when the A-menu is open
           - 0x0002 is set when the cash window is open? or hp/pp maybe?
           - 0x0007 is set when the main text window is open
0x3001D54: Ness items (16 bits each)
0x3001D70: Ness EXP
0x3001D80: Ness level
0x3001D84: Ness max HP
0x3001D86: Ness current HP
0x3001D8C: Ness max PP
0x3001D8E: Ness current PP
0x3001D94: Ailment?
           00: conscious
           01: unconscious
           02: diamondized
           03: paralyzed
           04: nauseous
           05: poisoned
           06: sunstroke
           07: sniffling
           08: mashroomized
           09: possessed
           0A: homesick
0x3001D95: Mashroomized flag?
0x3001D96: Sleep flag?
0x3001D97: Strange flag?
0x3001D98: Can't concentrate flag?
0x3001D99: Homesick flag?
0x3001DA3: Ness offense
0x3001DA4: Ness defense
0x3001DA5: Ness speed
0x3001DA6: Ness guts
0x3001DA7: Ness luck
0x3001DA8: Ness vitality
0x3001DA9: Ness IQ
0x3001DB5: Ness equipment
0x3001F04: Current party
0x3001F0B: Party character count (not sure how it's different from 3000AA2?)
0x3001F0C: Active party member flags
0x3001F6A: Ness PSI flags?
           0x01: Teleport alpha
           0x08: Teleport beta
0x3001FA4: Escargo Express items (36 of them)
0x3001FC8: event flags
0x30023D0: current cash balance
0x30023D4: current ATM balance
0x3002500: buttons being pressed
0x3002504: shadow of 0x3002500? delayed by one frame maybe?
0x30051EC: tile offset (usually 0x100)
0x30051F0: flag? gets set to 1 when you change rooms, goes back to 0 the first time you open a text window
0x3005224: menu depth
0x3005228: current text palette, << 0xC
0x3005230: addresses of all 11 windows
           [00]: A menu
           [01]: Money
           [02]: ?
           [03]: Action subject ("Who?", etc.)
           [04]: New equipment selection
           [05]: Offense/Defense
           [06]: Equip
           [07]: PSI list
           [08]: PSI classes
           [09]: PSI target/PP cost
           [0A]: PSI help
0x3005264: active window party member
0x3005270: address of tilemap start in WRAM, can use this to figure out X and Y

0x872E404: door destinations?

LDRB Rx,[Ry,#n]: n has range 0-31 (0x0-0x1F)
LDRH Rx,[Ry,#n]: n has range 0-62 (0x0-0x3E)
LDR Rx,[Ry,#n]: n has range 0-124 (0x0-0x7C) (0-1020 for SP- and PC-relative)

Custom WRAM: 2027FC0

Game code:         ~0x0     - ~0x264FB
Movement-y stuff?: ~0x264FC - ~0x3697E
Text:               0x3697F -  0x8C4B0
More code:          0xA1F6C -  0xFCE6B

EarthBound, Ness' Items: 7E99F1

Code sequences
--------------

80BAB64: draw and render PSI party target window
80C4C24: equip window renders four (None)s in a row
80C4F80: going left in equip window
80C4F84: going right in equip window

Subroutines
-----------

8001720: play sound effect r0
8005B9C: malloc? r0 = byte count
801C104: return random number from 0 to r0 (exclusive)
80A2E00: door-related? r0 = source, r1 = dest
80A334C: store r0 to window memory
80B8AE0: draw PSI target/PP cost window with PSI index r0
80BC670: check if currently selected character has item equipped
         r0: item index + 1
         returns: 1 if equipped, 0 otherwise or if index==0
80BD7AC: copy window buffer (primary/secondary)
         r0 = 0: copy from primary (2028A58) to secondary (2030A40)
         r0 = 1: copy from secondary to primary
80BD7F8: copy window buffer (primary/tertiary)
         r0 = 0: copy from primary (2028A58) to tertiary (2031248)
         r0 = 1: copy from tertiary to primary
80BE260: compute string pointer
         r0: pointer table
         r1: text base
         r2: index
80BE458: initialize window. If text pointer == 0, also draw window borders.
         r0: window pointer
         r1: text pointer
         r2: mystery halfword that gets copied to +0x2E
80BE4C8: initialize window. If text pointer == 0, also draw window borders.
         r0: window pointer
         r1: text pointer
         r2: mystery byte that gets copied to +0x42
         r3: mystery halfword that gets copied to +0x3E
         sp+0: mystery halfword that gets copied to +0x34 and +0x40 if the window enable flag is unset
80BF858: goods character selector state machine
         r0: window pointer
         returns: 0 if no action, 1 if descending deeper into window, -1 if exited
80C0A5C: render numbers on status window
80C1FBC: draw PSI window for character r0
80C239C: print PSI name with Greek letter
80C438C: check for cursor movements in PSI window
80C87D0: draw blank window and border (r0: window pointer)
80C8BE4: render main menu string to window r0
80C8FFC: render string to window r0
80C9634: render string (r1) to window (r0) at (x,y) (r2,r3)
80C96F0: render string (r1) to window (r0) at (x,2y) (r2,r3) using highlight [sp]
         (does not modify any window values)
80C980C: print next character (r0: window pointer)
80CA4BC: scroll text upwards (r0: window pointer)
80CA744: store the lowest r2 (e.g. 7) decimal digits of r0 as an array to r1; return position of highest non-zero digit
80CAB90: print window header string (r1) to RAM (r0) at tile ((r2 * 32) + r3)
80CABF8: print checkboard string (r1) to RAM (r0) at tile ((r2 * 32) + r3)
80D2E94: print party character name
80D30C4: related to printing numbers points in battle (r0 = window)
80D31F8: related to printing numbers outside of battle (r0 = window)
80D332C: related to printing names in battle (r0 = window)
80D3560: related to printing numbers outside of battle (r0 = window)
80D3858: related to printing numbers
80D3F0C: bump the HP/PP window of the given party member upwards
         r0: party member index
80D41D8: bump the HP/PP window of the current party member downwards
80D7154: count party members and store to 3000AA2
         then do some other stuff to the windows -- possibly drawing the HP/PP boxes?
80EBFD4: copy string from r0, of max length r1, to battle user slot, and terminate with [00 FF]
80EC004: get user string pointer
80EC010: copy string from r0, of max length r1, to battle target slot, and terminate with [00 FF]
80EC046: get target string pointer
80F49DC: divide r0 by r1, return quotient in r0

8B1B8B8 has a jump table with 13 entries for the [1A FF xx 00] code:
  00: ?
  01: PC name
  02: item name
  03: ?
  04: number
  05: PC name
  06: ?
  07: ?
  08: ?
  09: ?
  0A: ?
  0B: ?


Windows
-------

Window structure:
  0x00 - 0x03:  bitfield
    0x00000001: enable
    0x00000010: ? (checked when going right in goods character selection menu)
    0x00000020: signals to redraw the window and borders (cleared by C87D0)
    0x0000FFCE: ?
    0xFFFF0000: we're stealing these for our hacks
      0x0007:   pixel X value
      0xFFF8:   unused
  0x04 - 0x07:  start address of text being displayed
  0x08 - 0x0B:  same as above?
  0x0C - 0x0F:  menu text pointer
  0x10 - 0x13:  ?
  0x14 - 0x17:  text address offset
  0x18 - 0x1B:  ?
  0x1C - 0x1F:  when printing numbers: the current digit index to print
                when printing names: ?
  0x20 - 0x21:  area (width*height)
  0x22 - 0x23:  window X (text area, not including border)
  0x24 - 0x25:  window Y
  0x26 - 0x27:  window width (tiles, not including border)
  0x28 - 0x29:  window height
  0x2A - 0x2B:  relative text X
  0x2C - 0x2D:  relative text Y
  0x2E - 0x2F:  ?
  0x30 - 0x31:  frame delay counter (counts down to 0, once per frame, after calling 1B FF xx xx)
  0x32 - 0x33:  frame counter? e.g. for goods windows, it counts up to 0x10 and then loops back to 0
  0x34 - 0x35:  cursor X
  0x36 - 0x37:  cursor Y
  0x38 - 0x39:  ?
  0x3A - 0x3B:  ?
  0x3C - 0x3D:  ?
  0x3E - 0x3F:  ?
  0x40 - 0x41:  page number?
  0x42       :  cursor delta
  0x43       :  unused?
  0x44 - 0x4F:  ?

Custom codes
------------
5E FF xx: load value into memory
      01: plurality of enemies:
          01 = one
          02 = two
          03 = three or more
5F FF xx: set current rendering location to xx
60 FF xx: add xx to current rendering location

Enemy data
----------
$8739D1C - $873D6DB