Information: Load custom overworld music, without the reseting when changing screens. (Original Alttp always resets it to Overworld music when exiting most entrances).
Rom: expanded ALTTP rom (US), without header; pc w/o header ALTTP (US)
Screenshot:



Ups Patch: http://bszelda.zeldalegends.net/stuff/Con/custom_music.zip

Code Addresses: main code at $11A200, new music table at $11A300.

ASM

Code:


;CUSTOM MUSIC, ASM BY CONN


;Goal: load custom overworld music, without the reseting when changing screens. (Original Alttp always resets it to Overworld music).


lorom

org $008100
jsr $89d5  ;pc: 00/09d5 (after your sword charge no move)

org $0089d5
jsl $23a200
RTS

org $23a200
TAX ; transfer native value to X
SBC #$0F ; check if theme is in range 00-0F (overworld themes)
BCC $04 ; continue if yes
STZ $012C ; if no, set 012c to 00 and return to game
RTL
LDA $008c ; check overworld
cmp #$00
BNE $0b
LDA $008a
cmp #$00
BNE $04
STZ $012C ; if you are in dungeon/cave, set 012c to 00 and return to game
RTL
TXA ; regain native value X transfer to A
; now a comparison starts of themes you want to have replaced, this is overworld 02, lost woods 05, kakariko 07, dark world 09, skull woods 0d. This is necessary to not replace title screen, introduction, minigame, character selection, rabbit, rain, which is not on the map!
CMP #$02 ; if overworld theme is about to play jump to $A231 and replace, if not check if it is 05 and so forth.
BNE $03
JMP $A243
CMP #$05
BNE $03
JMP $A243
CMP #$07
BNE $03
JMP $A243
CMP #$09
BNE $03
JMP $A243
CMP #$0D
BNE $03
JMP $A243
STZ $012C ; if it is another theme (introduction, title screen -> return to game)
RTL
LDA $012C ; if theme is already loaded return to game (address is loaded twice)
CMP $0131
BNE $04
STZ $012C
RTL
LDX $040A ; load screen number to X
LDA $23A300,x ; select theme from table, in dependence of screen in X
STA $012C ; play theme
STA $2140
STA $0132
RTL

;The table at 11/a300 contains all 07 (kakariko). You simply need to replace these number by the number you like to have played.

;The table beginning at 01/4343 needs to be an exact copy of the table 11/a300 to avoid a music reset everytime you switch screens.