diff --git a/lec09/test.c b/lec09/test.c
new file mode 100644
index 0000000000000000000000000000000000000000..d5a6a9e23e9d3bab97e50420fb8f6eeb0d538047
--- /dev/null
+++ b/lec09/test.c
@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <math.h>
+// #### #### #### #### . #### #### #### #### - 32bit 
+// Sbit 15bit . 16bit 
+#define FX_Q_NUM 16
+#define FX_2_MINUS_16 1.52587890625e-05F
+#define FX_2_PLUS_16 (1<<16)
+#define FX_S_15_16 11516 // 1:singed 15 16
+#define FX_SYSTEM FX_S_15_16
+
+typedef int fixed32;
+
+fixed32 fromFloat(float fa)
+{
+	return (fixed32) (fa * FX_2_PLUS_16);
+}
+float toFloat(fixed32 xa)
+{
+	return ((float) (xa)) * FX_2_MINUS_16;
+}
+fixed32 fxAdd(fixed32 a, fixed32 b)
+{
+	return fromFloat((toFloat(a) + toFloat(b)));
+}
+fixed32 fxAdd2(fixed32 a, fixed32 b)
+{
+	return a+b;
+}
+
+int main()
+{
+	int i=0;
+	int ia, ib, ic, ic2;
+	float fa;
+	fscanf(stdin, "%d %d", &ia, &ib);
+	for (i=0; i< 64*256*256*256; i+=(256*256))
+	{
+		ic = fxAdd(i, i);
+		ic2 = fxAdd2(i, i);
+		fprintf(stdout, "%f + %f : %f, %f diff=%d\n", toFloat(i), toFloat(i),toFloat(ic),toFloat(ic2),ic-ic2);
+	}
+
+	fprintf(stdout, "%d + %d : %d\n", ia,ib,ic); 
+}
+
diff --git a/lec09/ulimit.txt b/lec09/ulimit.txt
new file mode 100644
index 0000000000000000000000000000000000000000..e8766e2e5f5b8df3bf610d9949d28b318cc77838
--- /dev/null
+++ b/lec09/ulimit.txt
@@ -0,0 +1,16 @@
+core file size          (blocks, -c) 0
+data seg size           (kbytes, -d) unlimited
+scheduling priority             (-e) 0
+file size               (blocks, -f) unlimited
+pending signals                 (-i) 256271
+max locked memory       (kbytes, -l) 65536
+max memory size         (kbytes, -m) unlimited
+open files                      (-n) 1024
+pipe size            (512 bytes, -p) 8
+POSIX message queues     (bytes, -q) 819200
+real-time priority              (-r) 0
+stack size              (kbytes, -s) 8192
+cpu time               (seconds, -t) unlimited
+max user processes              (-u) 256271
+virtual memory          (kbytes, -v) unlimited
+file locks                      (-x) unlimited