diff --git a/cpu-api/README.md b/cpu-api/README.md
index 42cfca3..add81a2 100644
--- a/cpu-api/README.md
+++ b/cpu-api/README.md
@@ -1,8 +1,32 @@
+## CPU API
 
-To compile, just type "make".
+This code is basically that found in [Interlude: Process API](http://pages.cs.wisc.edu/~remzi/OSTEP/cpu-api.pdf).
+
+To compile, just type:
+```
+prompt> make
+```
+
+See the highly primitive `Makefile` for details.
+
+Then run `p1`, `p2`, `p3`, or `p4`, as need be. Examples:
+
+```
+prompt> ./p1
+```
+
+```
+prompt> ./p2
+```
+
+```
+prompt> ./p3
+```
+
+```
+prompt> ./p4
+```
 
-See the highly primitive "Makefile" for details.
 
-Then run p1, p2, p3, or p4, as need be.