i = this.i;
		for(var layer = 0; layer < 2; layer++) {
			if ((this.plane & (layer+1)) == 0) { continue; }
			if (len == 0) {
				// draw a SuperChip 16x16 sprite
				for(var a = 0; a < 16; a++) {
					for(var b = 0; b < 16; b++) {
						var target = ((x+b) % rowSize) + ((y+a) % colSize)*rowSize;
						var source = ((this.m[i+(a*2)+(b > 7 ? 1:0)] >> (7-(b%8))) & 0x1) != 0;
						if (this.clipQuirks) {
							if ((x%rowSize)+b>=rowSize || (y%colSize)+a>=colSize) { source = 0; }
						}
						if (!source) { c