diff --git a/Visual Studio Projects/AltairZ80.vcproj b/Visual Studio Projects/AltairZ80.vcproj
index 64ee4836..390346e3 100644
--- a/Visual Studio Projects/AltairZ80.vcproj	
+++ b/Visual Studio Projects/AltairZ80.vcproj	
@@ -251,6 +251,19 @@
 				RelativePath="..\AltairZ80\i86_prim_ops.c"
 				>
 			</File>
+			<File
+				RelativePath="..\AltairZ80\ibc.c"
+				>
+			</File>
+			<File
+				RelativePath="..\AltairZ80\ibc_mcc_hdc.c"
+				>
+			</File>
+			<File
+				RelativePath="..\AltairZ80\ibc_smd_hdc.c"
+				>
+			</File>
+
 			<File
 				RelativePath="..\AltairZ80\insnsd.c"
 				>