diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4bafa56..fb25602 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -252,6 +252,7 @@ set (wsjtx_CXXSRCS
   main.cpp
   wsprnet.cpp
   WSPRBandHopping.cpp
+  TransmitTextEdit.cpp
   )
 
 set (wsjt_CXXSRCS
diff --git a/TransmitTextEdit.cpp b/TransmitTextEdit.cpp
new file mode 100644
index 0000000..dddce0e
--- /dev/null
+++ b/TransmitTextEdit.cpp
@@ -0,0 +1,53 @@
+#include "TransmitTextEdit.h"
+
+#include <QDebug>
+
+TransmitTextEdit::TransmitTextEdit(QWidget *parent):
+    QTextEdit(parent)
+{
+    connect(this, &QTextEdit::selectionChanged, this, &TransmitTextEdit::on_selectionChanged);
+    connect(this, &QTextEdit::cursorPositionChanged, this, &TransmitTextEdit::on_selectionChanged);
+}
+
+void TransmitTextEdit::markCharsSent(int n){
+    // update sent display
+    auto c = textCursor();
+    c.movePosition(QTextCursor::Start);
+    c.movePosition(QTextCursor::NextCharacter, QTextCursor::KeepAnchor, n);
+
+    auto ch = c.charFormat();
+    ch.setFontStrikeOut(true);
+    c.mergeCharFormat(ch);
+
+    // keep track
+    m_sent = n;
+}
+
+// override
+void TransmitTextEdit::setPlainText(const QString &text){
+    QTextEdit::setPlainText(text);
+    m_sent = 0;
+}
+
+// override
+void TransmitTextEdit::clear(){
+    QTextEdit::clear();
+    m_sent = 0;
+}
+
+// slot
+void TransmitTextEdit::on_selectionChanged(){
+    auto c = textCursor();
+    int start = c.selectionStart();
+    int end = c.selectionEnd();
+    if(end < start){
+        int x = end;
+        end = start;
+        start = x;
+    }
+    qDebug() << "selection" << start << end;
+
+    if(start <= m_sent){
+        qDebug() << "selection in protected zone" << start << "<=" << m_sent;
+    }
+}
diff --git a/TransmitTextEdit.h b/TransmitTextEdit.h
new file mode 100644
index 0000000..0360cd7
--- /dev/null
+++ b/TransmitTextEdit.h
@@ -0,0 +1,22 @@
+#ifndef TRANSMITTEXTEDIT_H
+#define TRANSMITTEXTEDIT_H
+
+#include <QTextEdit>
+
+class TransmitTextEdit : public QTextEdit
+{
+public:
+    TransmitTextEdit(QWidget *parent);
+
+    void markCharsSent(int n);
+    void setPlainText(const QString &text);
+    void clear();
+
+public slots:
+    void on_selectionChanged();
+
+private:
+    int m_sent;
+};
+
+#endif // TRANSMITTEXTEDIT_H
diff --git a/js8call.pro b/js8call.pro
index d978ff4..013ba79 100644
--- a/js8call.pro
+++ b/js8call.pro
@@ -83,7 +83,8 @@ SOURCES += \
     Inbox.cpp \
     messagewindow.cpp \
     SpotClient.cpp \
-    TCPClient.cpp
+    TCPClient.cpp \
+    TransmitTextEdit.cpp
 
 HEADERS  += qt_helpers.hpp \
   pimpl_h.hpp pimpl_impl.hpp \
@@ -118,7 +119,8 @@ HEADERS  += qt_helpers.hpp \
     messagewindow.h \
     SpotClient.h \
     TCPClient.h \
-    logbook/n3fjp.h
+    logbook/n3fjp.h \
+    TransmitTextEdit.h
 
 
 INCLUDEPATH += qmake_only
diff --git a/mainwindow.cpp b/mainwindow.cpp
index b79c04c..6852c27 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1918,6 +1918,9 @@ void MainWindow::initializeDummyData(){
     c.setCharFormat(f);
 #endif
 
+    ui->extFreeTextMsgEdit->setPlainText("HELLO BRAVE NEW WORLD");
+    ui->extFreeTextMsgEdit->markCharsSent(6);
+
     logHeardGraph("KN4CRD", "OH8STN");
     logHeardGraph("KN4CRD", "K0OG");
     logHeardGraph("K0OG", "KN4CRD");
@@ -5397,9 +5400,18 @@ void MainWindow::startTx2()
 void MainWindow::stopTx()
 {
   Q_EMIT endTransmitMessage ();
+
   auto dt = DecodedText(m_currentMessage.trimmed(), m_currentMessageBits, m_nSubMode);
   last_tx_label.setText("Last Tx: " + dt.message()); //m_currentMessage.trimmed());
 
+
+  // start message marker
+  // - keep track of the total message sent so far, and mark it having been sent
+  m_totalTxMessage.append(dt.message());
+  ui->extFreeTextMsgEdit->markCharsSent(m_totalTxMessage.length());
+  qDebug() << "total sent:\n" << m_totalTxMessage;
+  // end message marker
+
   m_btxok = false;
   m_transmitting = false;
   g_iptt=0;
@@ -6224,18 +6236,18 @@ QString MainWindow::createMessageTransmitQueue(QString const& text, bool reset){
 
   auto frames = buildMessageFrames(text);
 
-  m_txFrameQueue.append(frames);
-  m_txFrameCount = frames.length();
-
-  int freq = currentFreqOffset();
-  qDebug() << "creating message for freq" << freq;
-
   QStringList lines;
   foreach(auto frame, frames){
       auto dt = DecodedText(frame.first, frame.second, m_nSubMode);
       lines.append(dt.message());
   }
 
+  m_txFrameQueue.append(frames);
+  m_txFrameCount = frames.length();
+
+  int freq = currentFreqOffset();
+  qDebug() << "creating message for freq" << freq;
+
   // TODO: jsherer - parse outgoing message so we can add it to the inbox as an outgoing message
 
   auto joined = Varicode::rstrip(lines.join(""));
@@ -6265,6 +6277,9 @@ void MainWindow::resetMessageTransmitQueue(){
   m_txFrameCount = 0;
   m_txFrameQueue.clear();
   m_txMessageQueue.clear();
+
+  // reset the total message sent
+  m_totalTxMessage.clear();
 }
 
 QPair<QString, int> MainWindow::popMessageFrame(){
@@ -6382,6 +6397,11 @@ bool MainWindow::prepareNextMessageFrame()
   auto frame = f.first;
   auto bits = f.second;
 
+  // append this frame to the total message sent so far
+  // auto dt = DecodedText(frame, bits, m_nSubMode);
+  // m_totalTxMessage.append(dt.message());
+  // qDebug() << "total sent" << m_totalTxMessage;
+
   if(frame.isEmpty()){
     ui->nextFreeTextMsg->clear();
     updateTxButtonDisplay();
diff --git a/mainwindow.h b/mainwindow.h
index 952db2e..e5ae977 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -795,6 +795,7 @@ private:
   QString m_txTextDirtyLastText;
   QString m_txTextDirtyLastSelectedCall;
   QString m_lastTxMessage;
+  QString m_totalTxMessage;
   QDateTime m_lastTxTime;
   int m_timeDeltaMsMMA;
   int m_timeDeltaMsMMA_N;
diff --git a/mainwindow.ui b/mainwindow.ui
index 0ea9edd..bb69a9f 100644
--- a/mainwindow.ui
+++ b/mainwindow.ui
@@ -1133,7 +1133,7 @@ background-color:#6699ff;
           <string>Incoming and outgoing messages will appear here.</string>
          </property>
         </widget>
-        <widget class="QTextEdit" name="extFreeTextMsgEdit">
+        <widget class="TransmitTextEdit" name="extFreeTextMsgEdit">
          <property name="sizePolicy">
           <sizepolicy hsizetype="Expanding" vsizetype="Expanding">
            <horstretch>4</horstretch>
@@ -5848,6 +5848,11 @@ list. The list can be maintained in Settings (F2).</string>
    <extends>QPushButton</extends>
    <header>DoubleClickablePushButton.hpp</header>
   </customwidget>
+  <customwidget>
+   <class>TransmitTextEdit</class>
+   <extends>QTextEdit</extends>
+   <header>TransmitTextEdit.h</header>
+  </customwidget>
  </customwidgets>
  <tabstops>
   <tabstop>extFreeTextMsgEdit</tabstop>