ext = fixed.getContext("2d");

	// background
	fixed_context.fillStyle="#dbd5a0";
	fixed_context.fillRect(0, 0, w, h);
	
	// cells
	for(var i = 0; i < fixed_cell_xs.length; ++i) {
		fixed_context.fillStyle = fixed_cell_colors[i];
		fixed_context.fillRect(fixed_cell_xs[i], cell_y, cell_width, cell_height);
		
		fixed_context.textAlign = "center";
		fixed_context.textBaseline = "middle"; 
		fixed_context.font = "48px sans-serif";
		fixed_context.fillStyle = "#222222";		
		fixed_context.fillText(fixed_cell_bit