code: function() {
  		var cartridge = this.memory.cartridge,
  
  		      attrAddress = attrAddresses[ this.loopyV ],
  		      attribute = cartridge.readNameTable( attrAddress & 0x1fff ),
  
  		      nametableAddress = 0x2000 | ( this.loopyV & 0x0fff ),
  		      tileIndex = cartridge.readNameTable( nametableAddress & 0x1fff ),
  	          tile = cartridge.readTile( this.baseTable, tileIndex, this.y );
  
  		if ( tile ) {
  			this.renderTile(
  				tile,
  				palettes[ attribute & masks[ this.loopyV & 0xfff ] ]
  			);
  		}
  
  		this.incrementVX();
  	}
docs: Fetch background tile data.