diff --git a/free-programming-books-es.md b/free-programming-books-es.md
index 80ca13c0d55ccb36cdcd0957ec65df5b473c8d93..1be464481b7314d1f5816dd0f1766e89e8339167 100644
--- a/free-programming-books-es.md
+++ b/free-programming-books-es.md
@@ -8,7 +8,7 @@
 
 
 ###Assembly Language
-* [Machine Code for Beginners](http://www.worldofspectrum.org/infoseekid.cgi?id=2000227) (PDF) by Lisa Watts and Mike Wharton
+* [Machine Code for Beginners](http://www.worldofspectrum.org/infoseekid.cgi?id=2000227) (PDF) by Lisa Watts and Mike Wharton [Z80 and 6502 CPUs]
 
 ###Metalistas
 
diff --git a/free-programming-books.md b/free-programming-books.md
index 87bc2b7cb556c6de5ceae8a28beca23cb78f49ea..223389876e4fbbb1bd117a2b4513f9a5f126e84a 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -362,8 +362,8 @@
 * [Ralf Brown's Interrupt List](http://www.ctyme.com/rbrown.htm)
 
 ####Non-X86
-* [Machine Code for Beginners](http://www.worldofspectrum.org/infoseekid.cgi?id=2000227) (PDF) by Lisa Watts and Mike Wharton
-* [Machine Language for Beginners](http://archive.org/details/ataribooks-machine-language-for-beginners) by Richard Mansfield
+* [Machine Code for Beginners](http://www.worldofspectrum.org/infoseekid.cgi?id=2000227) (PDF) by Lisa Watts and Mike Wharton [Z80 and 6502 CPUs]
+* [Machine Language for Beginners](http://archive.org/details/ataribooks-machine-language-for-beginners) by Richard Mansfield [6502 CPU]
 
 
 ###Bash