Follow these rules, or bad things will happen! - Don't mix ROMs for different platforms - use generic BASIC with generic KERNAL, Mega65 BASIC with Mega65 KERNAL, etc. - Don't mix these ROMs with any other ROMs; the only exception is CHARGEN, this one is fully interchangeable. - Don't mix ROMs from different builds/versions (again, CHARGEN is an exception). - The generic ROM set should be compatible with any C64-compatible machine; platform-specific ROMs might not work on other platforms. Have fun!