The character ROM may be swapped into $D000-$DFFF where it …
The character ROM may be swapped into $D000-$DFFF where it is visible to the CPU. Since doing so necessitates swapping out the I/O registers, interrupts must be disabled first.
The character ROM may be swapped into $D000-$DFFF where it is visible to the CPU. Since doing so necessitates swapping out the I/O registers, interrupts must be disabled first.