diff --git a/code/AVR/SerialIO/SerialIO.ino b/code/AVR/SerialIO/SerialIO.ino
index e358e11..525d3ff 100644
--- a/code/AVR/SerialIO/SerialIO.ino
+++ b/code/AVR/SerialIO/SerialIO.ino
@@ -6,7 +6,7 @@
 // Enables serial communication between an Arduino and the Apple 1 PIA.
 // Based on Propeller source code from Briel Computers Apple 1 replica.
 
-// Port definitions
+// Port definitions (PIA pins)
 #define DA  A0
 #define RDA A1
 #define PB0 2
diff --git a/design/DesignSpark/schematic.sch b/design/DesignSpark/schematic.sch
index 34b1ddc..b7411a4 100644
Binary files a/design/DesignSpark/schematic.sch and b/design/DesignSpark/schematic.sch differ