diff --git a/Makefile b/Makefile
index cdbfd05..f11cbc5 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,5 @@
-CC65    =       $(HOME)/trees/cc65/bin/
+CC65    ?=       $(HOME)/trees/cc65/bin/
+
 CPU     =       6502
 
 apple2a.rom: a.out
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..aa0fe7a
--- /dev/null
+++ b/README.md
@@ -0,0 +1,3 @@
+Requires cc65 and https://github.com/bradgrantham/apple2e
+
+Set CC65 to the bin directory of your cc65 build.