diff --git a/mainwindow.cpp b/mainwindow.cpp
index 8869cbe..1fb4740 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -1034,6 +1034,9 @@ MainWindow::MainWindow(QDir const& temp_directory, bool multiple,
 
   auto enterFilter = new EnterKeyPressEater();
   connect(enterFilter, &EnterKeyPressEater::enterKeyPressed, this, [this](QKeyEvent *, QObject *){
+      if(ui->extFreeTextMsgEdit->isReadOnly()){
+          return;
+      }
       toggleTx(true);
   });
   ui->extFreeTextMsgEdit->installEventFilter(enterFilter);
@@ -5628,6 +5631,9 @@ QPair<QStringList, QStringList> MainWindow::buildFT8MessageFrames(QString const&
         }
 #endif
 
+        // once we find a directed call, data encode the rest of the line.
+        bool hasDirected = false;
+
         while(line.size() > 0){
           QString frame;
 
@@ -5646,10 +5652,11 @@ QPair<QStringList, QStringList> MainWindow::buildFT8MessageFrames(QString const&
           // if this parses to a standard FT8 free text message
           // but it can be parsed as a directed message, then we
           // should send the directed version
-          if(isFree && n > 0){
+          if(isFree && !hasDirected && n > 0){
               useDir = true;
+              hasDirected = true;
               frame = dirFrame;
-          } else if (isFree && m > 0) {
+          } else if ((isFree || hasDirected) && m > 0) {
               useDat = true;
               frame = datFrame;
           } else {
@@ -5693,6 +5700,13 @@ QPair<QStringList, QStringList> MainWindow::buildFT8MessageFrames(QString const&
 
               lines.append(line.left(n) + " ");
               line = line.mid(n);
+
+#if 0
+              // TODO: jsherer - this is how we'll prepend a 16-bit checksum to the message, just encode it in the data...
+              if(!line.isEmpty()){
+                line = Varicode::checksum16(line) + line;
+              }
+#endif
           }
 
           if(useDat){
@@ -5985,16 +5999,7 @@ QString MainWindow::calculateDistance(QString const& grid)
 // this function is called by auto_tx_mode, which is called by autoButton.clicked
 void MainWindow::on_startTxButton_toggled(bool checked)
 {
-    toggleTx(checked);
-}
-
-void MainWindow::toggleTx(bool start){
-    if(start){
-        // ensure the start button is checked
-        if(!ui->startTxButton->isChecked()){
-            ui->startTxButton->setChecked(true);
-        }
-
+    if(checked){
         createMessage(ui->extFreeTextMsgEdit->toPlainText());
         startTx();
     } else {
@@ -6003,6 +6008,12 @@ void MainWindow::toggleTx(bool start){
     }
 }
 
+void MainWindow::toggleTx(bool start){
+    if(start && ui->startTxButton->isChecked()) { return; }
+    if(!start && !ui->startTxButton->isChecked()) { return; }
+    ui->startTxButton->setChecked(start);
+}
+
 void MainWindow::splitAndSendNextMessage()
 {
 }
diff --git a/varicode.cpp b/varicode.cpp
index c8c55c6..68110bd 100644
--- a/varicode.cpp
+++ b/varicode.cpp
@@ -61,7 +61,7 @@ QMap<QString, int> directed_cmds = {
     {" ",     31 },  // send freetext
 };
 
-QSet<int> allowed_cmds = {0, 1, 2, 3, 4, /*5,*/ 10, 23, 24, 25, 26, 27, 28, 29, 30, 31};
+QSet<int> allowed_cmds = {0, 1, 2, 3, 4, 5, /*6,*/ 10, 23, 24, 25, 26, 27, 28, 29, 30, 31};
 
 QRegularExpression directed_re("^"
                                "(?<to>[A-Z0-9/]+)"
@@ -199,7 +199,7 @@ QString Varicode::formatPWR(int dbm){
     return QString("%1W").arg(mwatts/1000);
 }
 
-QString Varicode::checksum(QString const &input){
+QString Varicode::checksum16(QString const &input){
     auto fromBytes = input.toLocal8Bit();
     auto crc = CRC::Calculate(fromBytes.data(), fromBytes.length(), CRC::CRC_16_KERMIT());
     auto checksum = Varicode::pack16bits(crc);
@@ -209,12 +209,28 @@ QString Varicode::checksum(QString const &input){
     return checksum;
 }
 
-bool Varicode::checksumValid(QString const &checksum, QString const &input){
+bool Varicode::checksum16Valid(QString const &checksum, QString const &input){
     auto fromBytes = input.toLocal8Bit();
     auto crc = CRC::Calculate(fromBytes.data(), fromBytes.length(), CRC::CRC_16_KERMIT());
     return Varicode::pack16bits(crc) == checksum;
 }
 
+QString Varicode::checksum32(QString const &input){
+    auto fromBytes = input.toLocal8Bit();
+    auto crc = CRC::Calculate(fromBytes.data(), fromBytes.length(), CRC::CRC_32_BZIP2());
+    auto checksum = Varicode::pack32bits(crc);
+    if(checksum.length() < 6){
+        checksum += QString(" ").repeated(6-checksum.length());
+    }
+    return checksum;
+}
+
+bool Varicode::checksum32Valid(QString const &checksum, QString const &input){
+    auto fromBytes = input.toLocal8Bit();
+    auto crc = CRC::Calculate(fromBytes.data(), fromBytes.length(), CRC::CRC_32_BZIP2());
+    return Varicode::pack32bits(crc) == checksum;
+}
+
 QStringList Varicode::parseCallsigns(QString const &input){
     QStringList callsigns;
     QRegularExpression re(compound_callsign_pattern);
diff --git a/varicode.h b/varicode.h
index a37d381..7bc7e91 100644
--- a/varicode.h
+++ b/varicode.h
@@ -30,8 +30,11 @@ public:
     static QString formatSNR(int snr);
     static QString formatPWR(int dbm);
 
-    static QString checksum(QString const &input);
-    static bool checksumValid(QString const &checksum, QString const &input);
+    static QString checksum16(QString const &input);
+    static bool checksum16Valid(QString const &checksum, QString const &input);
+
+    static QString checksum32(QString const &input);
+    static bool checksum32Valid(QString const &checksum, QString const &input);
 
     static QStringList parseCallsigns(QString const &input);
     static QStringList parseGrids(QString const &input);