Learn and see the custom chips, their addresses and their content: $d000-$d0ff GTIA (pixel, color, sprites/player/missle, console, ...) $d100-$d1ff PBI $d200-$d2ff POKEY (paddle, keyboard, SIO, audio) $d300-$d3ff PAI (joystick, MMU) $d400-$d4ff ANTIC (DMA feed GITA with data) $d500-$d5ff Module port (R/W) $d600-$d7ff reserved (VBXE, SIDE, ...) $d800-$dfff Floating Point Packge (FPP)