I know this may sound like blasphemy, but have you thought of downloading a good Atari ST emulator and using one of the many excellent ASM editors for the ST. It's a 68000 based system with no chipsets. You learn all about the chip. Yes, i get it, it's not an Amiga per say, but you would need to learn chipsets on the Amiga (Copper for one.) And those chipsets are not 68000.
Just a thought.
