Edit Step Mine's MP

What you posted is the code that calculates MP cost in the menu. If you want to change the MP cost in battle I believe you need to modify this code instead:

Code:

C2/566E: E0 44 00     CPX #$0044      ; step mine
C2/5671: D0 09        BNE $567C
C2/5673: AD 64 18     LDA $1864       ; minutes / 30
C2/5676: C9 1E        CMP #$1E
C2/5678: AD 63 18     LDA $1863
C2/567B: 2A           ROL
C2/567C: 99 91 20     STA $2091,Y     ; set mp cost

To make this work like a normal spell, you can just replace the BNE with BRA. You will also need to modify the MP cost in spell properties.

To make it divide by 60 instead of 30, just replace the ROL with NOP. It's not literally dividing by 30 here, this is just some asm trickery that multiplies hours by 2 and then adds 1 if the minutes are 30 or greater.

I will go with turning it into normal spell. However, the menu still display the original MP formula. How to change that?