Fire Flower Palette Cycle

The short version is, if your patch does this -


- then your code in freespace should generally appear under a "freecode" command. The sequence above is known as "changing the data bank," and if your patch does this under a "freedata" command (as your patch does), it can lead to bugs if not crashes. The specific way this patch is set up happens to be safe, so we're all good this time. That said, until you become more familiar with intermediate/advanced-level ASM concepts, it's better to play it safe.

The takeaway: if you change the data bank, use freecode; if you don't change the data bank, freecode is still always safe, but freedata is more optimal.

Since your code already has to push and pull Y, though, you can sidestep the whole issue and make things more efficient by using X instead. If you put your index in X, you can use long addressing to load your palette table (LDA.l PaletteCycle,X). If you load from a table this way you don't have to change the data bank at all, with the tradeoff that you may only do this with X, not Y.

I'm not expecting all this to make perfect sense on a first read, just consider it something to look back to as you (hopefully) continue your ASM journey.

Also:

It is not needed, FYI.