diff --git a/README.md b/README.md
index 675f20b..a1f13b8 100644
--- a/README.md
+++ b/README.md
@@ -248,8 +248,10 @@ namely:
 
 * [Compound interest calculator](examples/compound.mu8a),
 * [Linear regression calculator](examples/linreg.mu8a),
-* [Hellorld!](examples/hellorld.mu8a) (a tribute to @UsagiElectric),
-* [FizzBuzz classic program](examples/fizzbuzz.mu8a),
+* [Hellorld!](examples/hellorld.mu8a) (a tribute to @UsagiElectric)
+  (requires I/O port 1 support),
+* [FizzBuzz classic program](examples/fizzbuzz.mu8a)
+  (requires I/O port 1 support),
 * [Bulls and Cows game](examples/moo.mu8a),
 * [Lunar Lander game](examples/lunar.mu8a).