A ROM chip found in Amigas.
This chip has the code that some parts of the operating system need. None of my references seem to tell exactly which parts, but I think at least the basic OS code required to boot the OS from disk is there. Also probably some "intensively used" things.
In general, I've noticed, you need Kickstart ROM version equal or greater than AmigaOS/Workbench version to run the latter.
You need to copy the contents of this ROM to file to use an emulator such as UAE; Copies of the ROMs can also be found from Amiga Forever.