diff --git a/doc/ALU-Pins.md b/doc/ALU-Pins.md
new file mode 100644
index 0000000..c7b65c1
--- /dev/null
+++ b/doc/ALU-Pins.md
@@ -0,0 +1,29 @@
+# ALU Pins
+
+| Nr| ACC  | RAM  | Y    |
+|:-:|:----:|:----:|:----:|
+| 0 | 1-27 | 1-39 | 1-22 |
+| 1 | 1-28 | 1-40 | 1-21 |
+| 2 | 1-29 | 1-41 | 1-20 |
+| 3 | 1-30 | 1-42 | 1-19 |
+| 4 | 1-31 | 1-5  | 1-18 |
+| 5 | 1-32 | 1-6  | 1-16 |
+| 6 | 1-6  | 1-7  | 1-14 |
+| 7 | 1-38 | 1-8  | 1-13 |
+| 8 | 2-27 | 2-39 | 2-21 |
+| 9 | 2-28 | 2-40 | 2-20 |
+| A | 2-29 | 2-2  | 2-19 |
+| B | 2-30 | 2-3  | 2-18 |
+| C | 2-31 | 2-5  | 2-16 |
+| D | 2-32 | 2-6  | 2-14 |
+| E | 2-37 | 2-7  | 2-13 |
+| F | 2-38 | 2-8  | 2-12 |
+
+| F | 1  | 2  |
+|:-:|:--:|:--:|
+| 0 | 43 | 44 |
+| 1 | 44 | 43 |
+| 2 | 1  | 42 |
+| 3 | 2  | 41 |
+
+CO (1-9) -> CI (2-24)