diff --git a/mainwindow.cpp b/mainwindow.cpp
index d8df364..cb0dc0f 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -10,24 +10,25 @@
 #include <QWidgetAction>
 #include <QFormLayout>
 #include <QSpinBox>
+#include <QShortcut>
 #include <QDebug>
 
 // system includes
 #include <stdexcept>
 
 namespace {
-constexpr int samplerates[] = { 44100, 48000, 96000, 192000 };
+    constexpr int samplerates[] = { 44100, 48000, 96000, 192000 };
 
-constexpr int refreshrates[] = { 1, 15, 30, 50, 60 };
+    constexpr int refreshrates[] = { 1, 15, 30, 50, 60 };
 
-constexpr int zoomlevels[] = { 50, 75, 100, 200, 400, 800 };
+    constexpr int zoomlevels[] = { 50, 75, 100, 200, 400, 800 };
 
-template<typename T>
-void setActionsEnabled(const T &actions, bool enabled)
-{
-    for(auto action : actions)
-        action->setEnabled(enabled);
-}
+    template<typename T>
+    void setActionsEnabled(const T &actions, bool enabled)
+    {
+        for(auto action : actions)
+            action->setEnabled(enabled);
+    }
 }
 
 MainWindow::MainWindow(QWidget *parent) :
@@ -142,6 +143,22 @@ MainWindow::MainWindow(QWidget *parent) :
         m_ui->menuDebug->addAction(widgetAction);
     }
 
+    // TODO cleanup when we have clean a strategy for implementing shortcuts and actions
+    auto toggleZen = new QShortcut(QKeySequence(tr("Z")), this);
+    connect(toggleZen, &QShortcut::activated, this, [=](){
+        setWindowFlags(windowFlags() ^ Qt::FramelessWindowHint);
+        setWindowState(windowState() ^ Qt::WindowFullScreen);
+        show();
+        menuBar()->setVisible(!menuBar()->isVisible());
+        statusBar()->setVisible(!statusBar()->isVisible());
+        QCursor *currentCursor = QGuiApplication::overrideCursor();
+        if(!currentCursor || *currentCursor != Qt::BlankCursor){
+            QGuiApplication::setOverrideCursor(Qt::BlankCursor);
+        }else{
+            QGuiApplication::restoreOverrideCursor();
+        }
+    });
+
     // autostart
     if (m_inputDevices.isEmpty())
     {
diff --git a/osciwidget.cpp b/osciwidget.cpp
index e6f3f21..77ff83c 100644
--- a/osciwidget.cpp
+++ b/osciwidget.cpp
@@ -9,8 +9,10 @@
 // system includes
 #include <cmath>
 
-qint32 framesForDuration(qint64 duration){
-    return qint32(44100 * duration / 1000000LL);
+namespace {
+    qint32 framesForDuration(qint64 duration){
+        return qint32(44100 * duration / 1000000LL);
+    }
 }
 
 
@@ -62,7 +64,7 @@ void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
 
     auto offset = std::distance(m_buffer.begin(), m_bufferOffset);
 
-    if(m_globalTimer.elapsed()-m_lastBufferUpdate > 5000)
+    if(m_globalTimer.elapsed()-m_lastBufferUpdate > 2000)
     {
         //qDebug() << "deleting: " << m_bufferOffset - m_buffer.begin() << m_buffer.size();
         // Delete drawn frames
@@ -123,7 +125,10 @@ void OsciWidget::drawBuffer(SampleBuffer::iterator &bufferPos, const SampleBuffe
     QPainter painter(&m_pixmap);
     painter.setRenderHint(QPainter::Antialiasing);
     painter.translate(m_pixmap.width()/2, m_pixmap.height()/2);
-    painter.scale(m_factor * m_pixmap.width() / 2.0, m_factor * m_pixmap.height() / 2.0);
+
+    // ensure 1:1 ratio
+    auto smallerSide = std::min(m_pixmap.width(), m_pixmap.height());
+    painter.scale(m_factor * smallerSide/ 2.0, m_factor * smallerSide/ 2.0);
 
     QPen pen;
     pen.setCosmetic(true); // let pen be scale invariant