For reference, here's a text file with Music and Sound Codes :
It's not complete, but it's what I compiled so far. Music Code is stored in $EB, and sounds are stored in $EC, $ED, $EE and $EF. I think there's some priority mechanism accorded to certain sounds relative to others, and relative to the music, but I'm not sure how this works exactly. Or maybe there's no mechanism at all and it's simply the last sound played that wins over others. Also, as far as I know, you can't use normal game sound effects while in the Selection Screen or Intro, and the sounds are actually made of music notes, so they use $EB.
If you find other sounds or something to be corrected, please let me know.
I found the code which apparently is in charge of setting the SFX specifically when picking up an item with the Sword. Took a bit of debugging, but I think I narrowed it down with FCEUX.
To pair it up to your disassembly, Trax, it's this code in Bank 7:
1E7F4: 20 80E8 JSR $E880
1E7F7: B5 AF LDA $AF,X
1E7F9: 29 7F AND #$7F ; keep bits .xxx xxxx
1E7FB: A8 TAY
1E7FC: B9 E6E7 LDA $E7E6,Y
1E7FF: 9D 1404 STA $0414,X
1E802: A9 08 LDA #$08 ; A = 08
1E804: 85 EF STA $EF ; Sound Effects Type 4
1E806: A9 00 LDA #$00 ; A = 00
1E808: 9D 0405 STA $0504,X
1E80B: 60 RTS
Specifically the LDA #$08, STA $EF which are in charge of setting the SFX for collecting the item.
I tried all of the possible sound effect types (EC, ED, EE, EF), and I found 2 suitable sounds which could be a good replacement.
Sword Hit on Shield Magic Spell
LDA #$02,STA $EC / LDA #$04,STA $EC
The thing is though, I am not too sure about which one to go to.
The only other sounds that could be a feasible option are the "Enemy Is Hit" or the "Enemy Destroyed" sounds, but I'm not too sure about those.
For anyone interested in wanting to hear what those sound like, go to 0x1E812 in a Hex editor and change this:
[A9 08 85 EF] for either [A9 02 85 EC] or [A9 04 85 EC]
For other two options, you could also try [A9 10 85 ED] or [A9 04 85 EF].
I will see which one of those 4 sounds I might choose for picking up an item.
Btw, Trax, from my tests, I got that Sound $02 in $EF seems to be part of the Fairy sound loop which plays when Link is transformed into one. Maybe this is dependent on location, and $01 in $EC seems to be when Link dies.
Oh I forgot to reply to this in particular:
Also, ever since v2.0, the Level Up screen has a weird detail.
Now the magic boost has changed to say "MGK.".
If it's gonna be shortened like that, shouldn't it be "MGC."?
(I believe Redux originally went with "MAG.", so there's that.)
Still true in v2.3 and this was without any extra patches, just so you know.
The change was intentional.
I made the change since MGK is an abbreviation often used in RPGs to refer to Magic/Magick/Magik.
MGC or MAG is also another one, but I feel like RPGs use MGK more often than those other two.