diff --git a/MC6809/test/Board.cpp b/MC6809/test/Board.cpp
index f7cd108..7fe5e4a 100644
--- a/MC6809/test/Board.cpp
+++ b/MC6809/test/Board.cpp
@@ -78,10 +78,14 @@ EightBit::MemoryMapping Board::mapping(uint16_t address) {
 
 void Board::Bus_WritingByte_Acia(EightBit::EventArgs&) {
 	updateAciaPins(EightBit::Chip::Low);
+	if (ACIA().selected())
+		ACIA().DATA() = DATA();
 }
 
 void Board::Bus_ReadingByte_Acia(EightBit::EventArgs&) {
 	updateAciaPins(EightBit::Chip::High);
+	if (ACIA().selected())
+		poke(ADDRESS(), ACIA().DATA());
 }
 
 void Board::updateAciaPins(const EightBit::Chip::PinLevel rw) {
diff --git a/MC6850/inc/MC6850.h b/MC6850/inc/MC6850.h
index 2055f90..586c2b0 100644
--- a/MC6850/inc/MC6850.h
+++ b/MC6850/inc/MC6850.h
@@ -99,6 +99,8 @@ namespace EightBit {
 
 		void step(int cycles);
 
+		bool selected();
+
 		void markTransmitComplete();
 		void markReceiveStarting();
 
@@ -114,8 +116,6 @@ namespace EightBit {
 	private:
 		uint8_t& status() { return m_status; }
 
-		bool selected();
-
 		void reset();
 
 		void step();
diff --git a/MC6850/src/MC6850.cpp b/MC6850/src/MC6850.cpp
index c94d541..fb6a2cb 100644
Binary files a/MC6850/src/MC6850.cpp and b/MC6850/src/MC6850.cpp differ