cc65 generated programs with the default setup run with the I/O area and the
kernal ROM enabled. Note that this is a non standard memory layout, and that
there is no "memory configuration index" for this layout. This means that
-special case has to be taken when changing the configuration, or calling any
+special care has to be taken when changing the configuration, or calling any
code that does this. The memory configuration register at $FF00 should
be saved and restored instead of relying on the memory configuration index
stored in the zero page.