diff --git a/README.md b/README.md
index 54f2893..d04e632 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ Arduino UNO, which does the programming of the GAL chip.
 
 Supported GAL chips:
 
-* Atmel ATF16V8B, ATF16V8BQL, ATF16V8C, ATF22V10B, ATF22V10C, ATF22V10CQZ 
+* Atmel ATF16V8B, ATF16V8BQL, ATF16V8C, ATF20V8B, ATF22V10B, ATF22V10C, ATF22V10CQZ 
 * Lattice GAL16V8A, GAL16V8B, GAL16V8D
 * Lattice GAL22V10B, GAL22V10D
 * National GAL16V8