go to mot.com and you'll find all the information you need about ppc asm programming...
If you want to port your programs thank you, but programming a pc with x86 and an amiga has little in common. You'll have to use the OS to select the screenmode. In amiga you can have any resolution and it has a different ID. In Amiga you can have multiple "screens" and the address of the screen can be in any place of the gfx ram, it's not in a fixed position, so you again will need to use the OS to get that address if you plan to write directly to the gfx ram for example.
Don't fancy about porting your apps without learning a bit how the AmigaOS API works. This is not a pc with MSDOS... this is not a primitive 8bit computer...
If you are going to port programs and not games you shouldn't "draw" the interface writing to the gfx card, you should use the components of the OS.
