To distinguish between the contents of the new ROMs on the Macintosh
Plus logic board and the contents of the new System file (3.0 and
greater), keep in mind the locations of the following features:
New ROMs only:
1. HD 20 Driver
2. Zoom Box
3. HFS
Both new ROMs and new System file (3.0 and greater):
4. AppleTalk Driver
5. System Font
6. Serial Driver
7. Numerics Package
8. Elementary Functions Package
Features 4 through 8 are contained in BOTH the ROMs and the System file in
order to maintain compatibility with the old ROMs.