--- a/pads2gpcb/decals.c	Sun Jan 31 01:39:31 2016 +0000
+++ b/pads2gpcb/decals.c	Sun Jan 31 01:57:38 2016 +0000
@@ -118,7 +118,82 @@
 static
 try_silk_circle()
 {
-	return(0);
+	int i, bad;
+	long x[2], y[2];
+	long centre_x, centre_y, diameter, thickness;
+
+	if (strcmp(input_line_fields[0], "CIRCLE"))
+		return(0);
+	if (input_line_nfields != 5)
+		return(0);
+	if (strcmp(input_line_fields[4], "0"))
+		return(0);
+	if (strcmp(input_line_fields[1], "2")) {
+		printf("line %d: silk CIRCLE piece ncoord != 2\n",
+			input_lineno);
+		return(0);
+	}
+	thickness = convert_input_dim(input_line_fields[2]);
+
+	bad = 0;
+	for (i = 0; i < 2; i++) {
+		get_line_internal();
+		parse_input_line_fields();
+		if (input_line_nfields != 2) {
+			printf("line %d: silk CIRCLE coord not 2 numbers\n",
+				input_lineno);
+			bad = 1;
+			continue;
+		}
+		x[i] = convert_input_dim(input_line_fields[0]);
+		y[i] = -convert_input_dim(input_line_fields[1]);
+	}
+	if (bad)
+		return(1);
+
+	/* find the centre and diameter */
+	if (x[0] == x[1]) {
+		centre_x = x[0];
+		if (y[0] < y[1]) {
+			diameter = y[1] - y[0];
+			centre_y = y[0] + diameter / 2;
+		} else if (y[1] < y[0]) {
+			diameter = y[0] - y[1];
+			centre_y = y[1] + diameter / 2;
+		} else
+			goto centre_diam_fail;
+	} else if (y[0] == y[1]) {
+		centre_y = y[0];
+		if (x[0] < x[1]) {
+			diameter = x[1] - x[0];
+			centre_x = x[0] + diameter / 2;
+		} else if (x[1] < x[0]) {
+			diameter = x[0] - x[1];
+			centre_x = x[1] + diameter / 2;
+		} else
+			goto centre_diam_fail;
+	} else {
+centre_diam_fail:
+		printf("line %d: unable to find circle centre and diameter\n",
+			input_lineno);
+		return(1);
+	}
+	if (diameter % 2)
+		printf("warning: line %d: circle diameter in nm is odd!\n",
+			input_lineno);
+
+	if (num_silk_arcs >= MAX_SILK_LINES) {
+		printf("Too many silk arcs!\n");
+		return(1);
+	}
+	silk_arcs[num_silk_arcs].centre_x = centre_x;
+	silk_arcs[num_silk_arcs].centre_y = centre_y;
+	silk_arcs[num_silk_arcs].width = diameter;
+	silk_arcs[num_silk_arcs].height = diameter;
+	silk_arcs[num_silk_arcs].start_angle = 0;
+	silk_arcs[num_silk_arcs].delta_angle = 360;
+	silk_arcs[num_silk_arcs].thickness = thickness;
+	return(1);
 }
 
 static void