diff --git a/CMakeLists.txt b/CMakeLists.txt
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -143,6 +143,8 @@ add_executable(${PROGRAM_NAME} WIN32
   src/versionnumber.cpp
   src/updatecheckdialog.cpp
   src/samplepack.cpp
+  src/source.cpp
+  src/sink.cpp
   misc/windows_icon.rc
   ${UI_FILES}
   ${RES_FILES}
diff --git a/src/sink.cpp b/src/sink.cpp
new file mode 100644
--- /dev/null
+++ b/src/sink.cpp
@@ -0,0 +1,51 @@
+/*
+  Copyright © 2017 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <QtGlobal>
+#include "sink.h"
+
+void Sink::connectFollower(Sink* sink)
+{
+    Q_ASSERT(!followers.contains(sink));
+
+    followers.append(sink);
+}
+
+void Sink::disconnectFollower(Sink* sink)
+{
+    Q_ASSERT(followers.contains(sink));
+
+    followers.removeOne(sink);
+}
+
+void Sink::feedIn(const SamplePack& data)
+{
+    for (auto sink : followers)
+    {
+        sink->feedIn(data);
+    }
+}
+
+void Sink::setNumChannels(unsigned nc, bool x)
+{
+    for (auto sink : followers)
+    {
+        sink->setNumChannels(nc, x);
+    }
+}
diff --git a/src/sink.h b/src/sink.h
new file mode 100644
--- /dev/null
+++ b/src/sink.h
@@ -0,0 +1,52 @@
+/*
+  Copyright © 2017 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef SINK_H
+#define SINK_H
+
+#include <QList>
+#include "samplepack.h"
+
+class Source;
+
+class Sink
+{
+public:
+    /// Connects a sink to get any data that this sink
+    /// gets. Connecting an already connected sink is an error.
+    void connectFollower(Sink* sink);
+    /// Disconnects a follower. Disconnecting an unconnected sink is
+    /// an error.
+    void disconnectFollower(Sink* sink);
+
+protected:
+    /// Entry point for incoming data. Re-implementations should
+    /// call this function to feed followers.
+    void feedIn(const SamplePack& data);
+    /// Is set by connected source. Re-implementations should call
+    /// this function to update followers.
+    void setNumChannels(unsigned nc, bool x);
+
+    friend Source;
+
+private:
+    QList<Sink*> followers;
+};
+
+#endif // SINK_H
diff --git a/src/source.cpp b/src/source.cpp
new file mode 100644
--- /dev/null
+++ b/src/source.cpp
@@ -0,0 +1,53 @@
+/*
+  Copyright © 2017 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <QtGlobal>
+
+#include "source.h"
+
+void Source::connect(Sink* sink)
+{
+    Q_ASSERT(!sinks.contains(sink));
+
+    sinks.append(sink);
+}
+
+void Source::disconnect(Sink* sink)
+{
+    Q_ASSERT(sinks.contains(sink));
+
+    sinks.removeOne(sink);
+}
+
+void Source::feedOut(const SamplePack& data) const
+{
+    for (auto sink : sinks)
+    {
+        sink->feedIn(data);
+    }
+}
+
+/// Updates "number of channels" of connected sinks
+void Source::feedNumChannels(unsigned nc, bool x) const
+{
+    for (auto sink : sinks)
+    {
+        sink->setNumChannels(nc, x);
+    }
+}
diff --git a/src/source.h b/src/source.h
new file mode 100644
--- /dev/null
+++ b/src/source.h
@@ -0,0 +1,51 @@
+/*
+  Copyright © 2017 Hasan Yavuz Özderya
+
+  This file is part of serialplot.
+
+  serialplot is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  serialplot is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef SOURCE_H
+#define SOURCE_H
+
+#include <QList>
+
+#include "sink.h"
+#include "samplepack.h"
+
+class Source
+{
+public:
+    virtual bool hasX() const = 0;
+    virtual unsigned numChannels() const = 0;
+
+    /// Connects a sink to this source. Trying to connect an already
+    /// connected sink is an error.
+    void connect(Sink* sink);
+    /// Disconnects an already connected sink. Trying to disconnect an
+    /// unconnected sink is an error.
+    void disconnect(Sink* sink);
+
+protected:
+    /// Feeds "in" given data to connected sinks
+    void feedOut(const SamplePack& data) const;
+    /// Updates "number of channels" of connected sinks
+    void feedNumChannels(unsigned nc, bool x = false) const;
+
+private:
+    QList<Sink*> sinks;
+};
+
+#endif // SOURCE_H