fsetX = 0;
		c.dataset.offsetY = 0;
		c.dataset.scale = 1;
		c.dataset.brightness = 1;
		c.dataset.contrast = 100;
	}

	function viewport_offset_cpu2(dx, dy) {
		const c = cpu2;
		//console.log(`dxy ${dx} ${dy}`);
		c.dataset.offsetX = Number(c.dataset.offsetX) + Number(dx);
		c.dataset.offsetY = Number(c.dataset.offsetY) + Number(dy);
	}

	function viewport_scale_cpu2(x, y, lds) {
		const c = cpu2;
		//console.log(`S x=${x} y=${y} lds=${lds} ox=${offsetX} oy=${offsetY}`)
		const cx = (x - Number(c.dataset.