diff --git a/README.md b/README.md
index 6504f71da..841f7cdb7 100644
--- a/README.md
+++ b/README.md
@@ -80,6 +80,7 @@ for other operating systems, you may [build the source](#developer-info).
   - TED used in Commodore Plus/4
   - Casio PV-1000
   - TIA used in Atari 2600
+    - including software tuning engine (TIunA)
   - POKEY used in Atari 8-bit computers
   - **Game Boy**
     - including SOFTWARE ENVELOPES (zombie mode)
diff --git a/demos/a2600/twin.fur b/demos/a2600/twin.fur
new file mode 100644
index 000000000..6353c182d
Binary files /dev/null and b/demos/a2600/twin.fur differ
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index f5b8c0390..af2b7dec6 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -1669,7 +1669,7 @@ void FurnaceGUI::openFileDialog(FurnaceGUIFileDialogs type) {
       if (!dirExists(workingDirSong)) workingDirSong=getHomeDir();
       hasOpened=fileDialog->openLoad(
         _("Open File"),
-        {_("compatible files"), "*.fur *.dmf *.mod *.s3m *.xm *.it *.fc13 *.fc14 *.smod *.fc *.ftm *.0cc *.dnm *.eft *.fub *.tfe",
+        {_("compatible files"), "*.fur *.dmf *.mod *.s3m *.fc13 *.fc14 *.smod *.fc *.ftm *.0cc *.dnm *.eft *.fub *.tfe",
          _("all files"), "*"},
         workingDirSong,
         dpiScale