To emulate an Amiga 1200, you need the firmware. These are copyrighted, but you can acquire them legally:

: A1200 packs highlight titles like Banshee , Alien Breed 3D , and Guardian , which utilized the AGA chipset to deliver visuals and speed that the older Amiga 500 simply could not match. The Legal and Ethical Landscape

At the center of every Amiga 1200 experience is the . Unlike modern PCs that rely entirely on disk-based operating systems, the Amiga stored its core firmware—the kernel of its operating system—on physical ROM chips. For the A1200, this was typically Kickstart 3.0 or 3.1 .

Ironically, if you are restoring a real Amiga 1200, you might need a ROM pack to burn new EPROMs. Vintage computer repair shops use these packs to create physical chips to replace corroded ones.