diff --git a/README.md b/README.md
index 696f47a..dbc852c 100644
--- a/README.md
+++ b/README.md
@@ -23,5 +23,5 @@ Build order as per the website. Cost for each gate in NAND in brackets.
 - [x] `Or8Way` (21)
 - [x] `Mux4Way16` (339)
 - [x] `Mux8Way16` (791)
-- [ ] `DMux4Way` ()
+- [x] `DMux4Way` (37, Fun)
 - [ ] `DMux8Way` ()
diff --git a/projects/01/DMux4Way.hdl b/projects/01/DMux4Way.hdl
index cfdfcbb..eaefeee 100644
--- a/projects/01/DMux4Way.hdl
+++ b/projects/01/DMux4Way.hdl
@@ -16,5 +16,28 @@ CHIP DMux4Way {
     OUT a, b, c, d;
 
     PARTS:
-    // Put your code here:
-}
\ No newline at end of file
+
+    /**
+     * Demultiplexor:
+     * {x, y} = {in, 0} if sel[0] == 0
+     *          {0, in} if sel[0] == 1
+     */
+    DMux(in=in, sel=sel[0], a=x, b=y);
+    // Now we can copy x,y to abcd as {x|0,y|0,x|0,y|0}
+    // depending on sel[1]
+
+    // sel| 00 | 01 || 10 | 11
+    //S[1]|    0    ||    1
+    //----|----|----||----|---
+    // x  | in | 0  || in | 0
+    // y  | 0  | in || 0  | in
+    //----|----|----||----|---
+    // a  | in | 0  || 0  | 0
+    // b  | 0  | in || 0  | 0
+    // c  | 0  | 0  || in | 0
+    // d  | 0  | 0  || 0  | in
+    Mux(a=x, b=false, sel=sel[1], out=a);
+    Mux(a=y, b=false, sel=sel[1], out=b);
+    Mux(a=false, b=x, sel=sel[1], out=c);
+    Mux(a=false, b=y, sel=sel[1], out=d);
+}
diff --git a/projects/01/DMux4Way.out b/projects/01/DMux4Way.out
new file mode 100644
index 0000000..9dd708f
--- /dev/null
+++ b/projects/01/DMux4Way.out
@@ -0,0 +1,9 @@
+| in  | sel  |  a  |  b  |  c  |  d  |
+|  0  |  00  |  0  |  0  |  0  |  0  |
+|  0  |  01  |  0  |  0  |  0  |  0  |
+|  0  |  10  |  0  |  0  |  0  |  0  |
+|  0  |  11  |  0  |  0  |  0  |  0  |
+|  1  |  00  |  1  |  0  |  0  |  0  |
+|  1  |  01  |  0  |  1  |  0  |  0  |
+|  1  |  10  |  0  |  0  |  1  |  0  |
+|  1  |  11  |  0  |  0  |  0  |  1  |