We were discussing doing fire effects. I don't remember if the ipl was mentioned or not there.
And yes, a hacked ipl. You can't change some of it because bios does a match check on the code. But if you disassemble the code, you can see how it works. You can pre-load palettes, a BAT, and graphics - the catch being Huc/Magikit doesn't expect those things, so you have to patch the iso to make it work.
What's really interesting is that bios loads 2 sectors (4K) for the ipl - but only about 512 bytes are actually used.
There's an empty space (that has to be all 0's for the check) that you can use for variables because...
you can set your execute address to be -in- the ipl area. And run a splash screen directly from the ipl
For those who understand any of that, bios also stashes the sector number of the ipl for you in the user data area, iirc, so you can load your program after the splash screen is done.
I understand using overlays to load things, and it's not a bad idea. I just don't like the fact that it ends up loading 32K of HuC libraries (most of which it won't use) just to set up vram. And I hate trying to maintain multiple copies of the same basic program because I have to keep re-loading slightly different versions of it...