diff --git a/devsetup.cpp b/devsetup.cpp
index 1264ff593..9e4b8da5d 100644
--- a/devsetup.cpp
+++ b/devsetup.cpp
@@ -139,6 +139,7 @@ void DevSetup::initDlg()
   m_paInDevice=m_inDevList[m_nDevIn];
   m_paOutDevice=m_outDevList[m_nDevOut];
   ui.cbEnableCAT->setChecked(m_catEnabled);
+  ui.cbDTRoff->setChecked(m_bDTRoff);
   ui.catPortComboBox->setEnabled(m_catEnabled);
   ui.rigComboBox->setEnabled(m_catEnabled);
   ui.serialRateComboBox->setEnabled(m_catEnabled);
@@ -397,12 +398,16 @@ void DevSetup::on_testCATButton_clicked()
     sprintf(buf,"%d",m_stopBits);
     rig->setConf("stop_bits",buf);
     rig->setConf("serial_handshake",m_handshake.toAscii().data());
+    if(m_bDTRoff) {
+      rig->setConf("rts_state","OFF");
+      rig->setConf("dtr_state","OFF");
+    }
     rig->open();
     m_bRigOpen=true;
   }
   catch (const RigException &Ex) {
     m_bRigOpen=false;
-    msgBox("Failed to open rig (A)");
+    msgBox("Failed to open rig (devsetup)");
     return;
   }
   double fMHz=rig->getFreq(RIG_VFO_CURR)/1000000.0;
@@ -413,7 +418,6 @@ void DevSetup::on_testCATButton_clicked()
 
 void DevSetup::on_testPTTButton_clicked()
 {
-  int iret=0;
   m_test=1-m_test;
   if(m_pttMethodIndex==1 or m_pttMethodIndex==2) {
     ptt(m_pttPort,m_test,&m_iptt,&m_COMportOpen);
@@ -422,3 +426,8 @@ void DevSetup::on_testPTTButton_clicked()
     rig->setPTT((ptt_t)m_iptt, RIG_VFO_CURR);
   }
 }
+
+void DevSetup::on_cbDTRoff_toggled(bool checked)
+{
+  m_bDTRoff=checked;
+}
diff --git a/devsetup.h b/devsetup.h
index c9186f6ec..65477bc80 100644
--- a/devsetup.h
+++ b/devsetup.h
@@ -5,7 +5,7 @@
 #include <QProcess>
 #include <QMessageBox>
 #include "ui_devsetup.h"
-#include "mainwindow.h"
+#include <hamlib/rigclass.h>
 
 class DevSetup : public QDialog
 {
@@ -46,6 +46,7 @@ public:
   bool    m_catEnabled;
   bool    m_After73;
   bool    m_bRigOpen;
+  bool    m_bDTRoff;
 
   QString m_myCall;
   QString m_myGrid;
@@ -57,8 +58,6 @@ public:
   QStringList m_macro;
   QStringList m_dFreq;
 
-  Rig* rig;
-
   QProcess p4;
   QMessageBox msgBox0;
 
@@ -85,9 +84,14 @@ private slots:
 
   void on_testPTTButton_clicked();
 
+  void on_cbDTRoff_toggled(bool checked);
+
 private:
+  Rig* rig;
   void msgBox(QString t);
   Ui::DialogSndCard ui;
 };
 
+extern int ptt(int nport, int ntx, int* iptt, int* nopen);
+
 #endif // DEVSETUP_H
diff --git a/devsetup.ui b/devsetup.ui
index 33119f228..29af0e20c 100644
--- a/devsetup.ui
+++ b/devsetup.ui
@@ -772,6 +772,26 @@
            </item>
           </widget>
          </item>
+         <item>
+          <spacer name="horizontalSpacer_13">
+           <property name="orientation">
+            <enum>Qt::Horizontal</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>40</width>
+             <height>20</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+         <item>
+          <widget class="QCheckBox" name="cbDTRoff">
+           <property name="text">
+            <string>RTS/DTR OFF</string>
+           </property>
+          </widget>
+         </item>
          <item>
           <spacer name="horizontalSpacer_5">
            <property name="orientation">
diff --git a/mainwindow.cpp b/mainwindow.cpp
index 79d21dfe4..da48c366a 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -17,6 +17,7 @@ static int nc1=1;
 wchar_t buffer[256];
 bool btxok;                           //True if OK to transmit
 bool btxMute;
+bool bDTRoff;
 double outputLatency;                 //Latency in seconds
 double dFreq[]={0.136,0.4742,1.838,3.578,5.357,7.078,10.130,14.078,
            18.104,21.078,24.918,28.078,50.293,70.091,144.489,432.178};
@@ -400,6 +401,7 @@ void MainWindow::writeSettings()
   settings.setValue("Runaway",m_runaway);
   settings.setValue("Tx2QSO",m_tx2QSO);
   settings.setValue("MultipleOK",m_bMultipleOK);
+  settings.setValue("DTRoff",bDTRoff);
   settings.endGroup();
 }
 
@@ -512,6 +514,7 @@ void MainWindow::readSettings()
   ui->actionTx2QSO->setChecked(m_tx2QSO);
   m_bMultipleOK=settings.value("MultipleOK",false).toBool();
   ui->actionAllow_multiple_instances->setChecked(m_bMultipleOK);
+  bDTRoff=settings.value("DTRoff",false).toBool();
 
   if(!ui->actionLinrad->isChecked() && !ui->actionCuteSDR->isChecked() &&
     !ui->actionAFMHot->isChecked() && !ui->actionBlue->isChecked()) {
@@ -619,6 +622,7 @@ void MainWindow::on_actionDeviceSetup_triggered()               //Setup Dialog
   dlg.m_stopBitsIndex=m_stopBitsIndex;
   dlg.m_handshake=m_handshake;
   dlg.m_handshakeIndex=m_handshakeIndex;
+  dlg.m_bDTRoff=bDTRoff;
 
   if(m_bRigOpen) {
     rig->close();
@@ -654,6 +658,7 @@ void MainWindow::on_actionDeviceSetup_triggered()               //Setup Dialog
     m_stopBitsIndex=dlg.m_stopBitsIndex;
     m_handshake=dlg.m_handshake;
     m_handshakeIndex=dlg.m_handshakeIndex;
+    bDTRoff=dlg.m_bDTRoff;
 
 #ifdef WIN32
     if(dlg.m_pskReporter!=m_pskReporter) {
@@ -2621,13 +2626,17 @@ void MainWindow::rigOpen()
     sprintf(buf,"%d",m_stopBits);
     rig->setConf("stop_bits",buf);
     rig->setConf("serial_handshake",m_handshake.toAscii().data());
+    if(bDTRoff) {
+      rig->setConf("rts_state","OFF");
+      rig->setConf("dtr_state","OFF");
+    }
     rig->open();
     m_bRigOpen=true;
   }
   catch (const RigException &Ex) {
     m_catEnabled=false;
     m_bRigOpen=false;
-    msgBox("Failed to open rig (B)");
+    msgBox("Failed to open rig (mainwindow)");
     delete rig;
   }
 }
diff --git a/mainwindow.h b/mainwindow.h
index 6740b7179..d43cc06e7 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -255,6 +255,8 @@ private:
     bool    m_tune;
     bool    m_bRigOpen;
     bool    m_bMultipleOK;
+//    bool    junk999;
+
     char    m_decoded[80];
 
     float   m_pctZap;