diff --git a/README.md b/README.md
index 472d501..18603fe 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,12 @@
 # test3d-tools
 Tools for working with stuff from Test3D
+## sasm.lua
+A super simple mnemonics-to-opcodes and opcodes-to-mnemonics program. Usage:
+### Compiling
+```
+lua sasm.lua -c in > out
+```
+### Decompiling
+```
+lua sasm.lua -d out > in
+```