By disabling I/O, $D000-$DFFF becomes free RAM. The color R…

Twetch · November 14, 2019

By disabling I/O, $D000-$DFFF becomes free RAM. The color RAM at $D800 is swapped along with the I/O registers and this area can be used for static graphics data such as character sets since the VIC-II cannot see the I/O registers or color RAM.