The Super Nintendo uses a 16-bit 65C816 CPU running at 3.58 MHz (NTSC) with 24-bit addressing for up to 16MB. It has 128KB of main RAM and separate PPU for graphics.

$00-$3F: System area (RAM mirrors, I/O)
$40-$7D: ROM/expansion
$7E-$7F: 128KB Work RAM
$80-$FF: Mirror of $00-$7F

Mode 0: 4 layers, 4 colors each
Mode 1: 2 layers 16-color, 1 layer 4-color
Mode 2: 2 layers with offset-per-tile
Mode 3: 1 layer 256-color, 1 layer 16-color
Mode 7: Rotation/scaling (one 256-color layer)