replace uses of minus one

engine/HoF_room_pc.asm

@@ -29,7 +29,7 @@ HallOfFamePC: ; 7405c (1d:405c)
 	ld c, 128
 	call DelayFrames
 	xor a
-	ld [wNumCreditsMonsDisplayed - 1], a ; not read
+	ld [wUnusedCD3D], a ; not read
 	ld [wNumCreditsMonsDisplayed], a
 	jp Credits
 

engine/menu/prize_menu.asm

@@ -179,7 +179,7 @@ LoadCoinsToSubtract: ; 528b1 (14:68b1)
 	ld hl,wd141 ; first prize's price
 	add hl,de ; get selected prize's price
 	xor a
-	ld [hCoins - 1],a
+	ld [hUnusedCoinsByte],a
 	ld a,[hli]
 	ld [hCoins],a
 	ld a,[hl]

engine/overworld/hidden_items.asm

@@ -67,7 +67,7 @@ HiddenCoins: ; 76799 (1d:6799)
 	and a
 	ret nz
 	xor a
-	ld [hCoins - 1], a
+	ld [hUnusedCoinsByte], a
 	ld [hCoins], a
 	ld [hCoins + 1], a
 	ld a, [wHiddenObjectFunctionArgument]

hram.asm

@@ -137,6 +137,9 @@ hNPCPlayerRelativePosPerspective EQU $FF9B
 ; 1 = target is to the west
 hNPCPlayerRelativePosFlags EQU $FF9D
 
+; some code zeroes this for no reason when writing a coin amount
+hUnusedCoinsByte EQU $FF9F
+
 hMoney EQU $FF9F ; 3-byte BCD number
 hCoins EQU $FFA0 ; 2-byte BCD number
 

scripts/celadongamecorner.asm

@@ -170,7 +170,7 @@ CeladonGameCornerText2: ; 48ca9 (12:4ca9)
 	ld c, $3
 	predef SubBCDPredef
 	xor a
-	ld [hCoins - 1], a
+	ld [hUnusedCoinsByte], a
 	ld [hCoins], a
 	ld a, $50
 	ld [hCoins + 1], a
@@ -238,7 +238,7 @@ CeladonGameCornerText5: ; 48d4a (12:4d4a)
 	call Has9990Coins
 	jr nc, .asm_48d8e
 	xor a
-	ld [hCoins - 1], a
+	ld [hUnusedCoinsByte], a
 	ld [hCoins], a
 	ld a, $10
 	ld [hCoins + 1], a
@@ -320,7 +320,7 @@ CeladonGameCornerText9: ; 48dd9 (12:4dd9)
 	call Has9990Coins
 	jr nc, .asm_48e18
 	xor a
-	ld [hCoins - 1], a
+	ld [hUnusedCoinsByte], a
 	ld [hCoins], a
 	ld a, $20
 	ld [hCoins + 1], a
@@ -373,7 +373,7 @@ CeladonGameCornerText10: ; 48e3b (12:4e3b)
 	call Has9990Coins
 	jr z, .asm_48e7a
 	xor a
-	ld [hCoins - 1], a
+	ld [hUnusedCoinsByte], a
 	ld [hCoins], a
 	ld a, $20
 	ld [hCoins + 1], a

wram.asm

@@ -733,6 +733,8 @@ wWhichTrade:: ; cd3d
 ; which entry from TradeMons to select
 
 wTrainerSpriteOffset:: ; cd3d
+
+wUnusedCD3D:: ; cd3d
 	ds 1
 
 wSSAnneSmokeX:: ; cd3e