diff --git a/src/download_thread.cpp b/src/download_thread.cpp
index f82c8fd..8ba9b18 100644
--- a/src/download_thread.cpp
+++ b/src/download_thread.cpp
@@ -109,6 +109,116 @@ void DownloadThread::run() {
     qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
                 << "               DownloadThread::run(): Filename:" << m_hw->dcDownloadFileName();
 
+    QDateTime const start = QDateTime::currentDateTime();
+
+#if 1
+    QFile fn(m_hw->dcDownloadFileName());
+
+    if (!fn.exists()) {
+        // output via CONSOLE() etc
+        qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                    << "               DownloadThread::run(): Filename:" << m_hw->dcDownloadFileName() << "DOES NOT EXIST";;
+    } else {
+
+        qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                    << "DownloadThread::run(): DC-CONTROLLER SW-VERSION BEFORE"
+                    << m_hw->dc_getSWversion();
+
+        // load binary device controller file into memory
+        QByteArray ba = loadBinaryDCFile(m_hw->dcDownloadFileName());
+        if (ba.size() > 0) {
+            uint16_t const totalBlocks = (((ba.size())%64)==0) ? (ba.size()/64) : (ba.size()/64)+1;
+            m_hw->dcDownloadSetTotalBlockNumber(totalBlocks);
+
+            // fill last block of data to be sent with 0xFF
+            ba = ba.leftJustified(totalBlocks*64, (char)(0xFF));
+
+            qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                        << "DownloadThread::run(): TOTAL NUMBER OF BYTES TO SEND TO DC" << ba.size();
+            qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                        << "DownloadThread::run(): TOTAL NUMBER OF BLOCKS" << totalBlocks;
+
+            m_hw->dc_autoRequest(true); // turn auto-request setting on
+
+            m_hw->request_DC2_HWversion();
+            m_hw->request_DC2_SWversion();
+            QThread::sleep(1);
+
+            // m_hw->dc_autoRequest(false); // turn auto-request setting on
+
+            resetDeviceController();
+
+            qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                        << "DownloadThread::run(): RESET DEVICE-CONTROLLER";
+
+            if (startBootloader()) {
+
+                qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                            << "DownloadThread::run(): STARTED BOOT-LOADER";
+
+                m_hw->dc_autoRequest(false);// turn auto-request setting off for
+                                            // download of binary dc
+
+                qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                            << "DownloadThread::run(): TOTAL NUMBER OF FIRMWARE BLOCKS" << totalBlocks;
+
+                int currentBlock = 0; // download of binary dc
+                DownloadResult res = DownloadResult::OK;
+
+                while (res != DownloadResult::ERROR &&  currentBlock < totalBlocks) {
+                    if ((res = sendNextAddress(currentBlock)) != DownloadResult::ERROR) {
+                        if ((res = sendNextDataBlock(ba, currentBlock)) != DownloadResult::ERROR) {
+                            m_hw->dcDownloadSetCurrentBlockNumber(currentBlock);
+
+                            qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                                        << "DownloadThread::run(): currentBlockNumber ..." << currentBlock;
+
+                            currentBlock += 1;
+                        }
+                    }
+                }
+
+                qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                            << QString("DownloadThread::run(): last 64-byte block %1").arg(currentBlock);
+
+                int const rest = ba.size() % 64;
+                int const offset = ba.size() - rest;
+                char const *startAddress = ba.constData() + offset;
+
+                if (rest > 0) {
+                    // SHOULD NEVER HAPPEN !!!
+                    uint8_t local[66];
+                    memset(local, 0xFF, sizeof(local));
+                    memcpy(local, startAddress, rest);
+                    qCritical() << "DownloadThread::run(): ERROR SEND REMAINING" << rest << "BYTES";
+                    m_hw->bl_sendDataBlock(64, local);
+                } else {
+                    m_hw->bl_sendLastBlock();
+                    m_hw->dcDownloadSetCurrentBlockNumber(currentBlock);
+
+                    qCritical() << "DownloadThread::run(): currentBlockNumber" << currentBlock;
+                    // QThread::msleep(250);
+                }
+                qCritical() << "DownloadThread::run(): last result" << (int)sendStatus(m_hw->bl_wasSendingDataOK());
+
+                stopBootloader();   // stop bootloader several times: if it
+                QThread::sleep(1);  // is not stopped, then the PSA has to be
+            }
+            // restarted manually (!!!)
+            stopBootloader();
+            QThread::sleep(1);
+        }
+
+        qCritical() << QDateTime::currentDateTime().time().toString(Qt::ISODateWithMs)
+                    << "DownloadThread::run(): STOPPED BOOT-LOADER";
+
+        stopBootloader();   // there is no harm in stopping the bootloader even
+                            // if it was not started at all
+
+        m_hw->dc_autoRequest(true);
+    }
+
+#else // test
     // load binary device controller file into memory
     QByteArray ba = loadBinaryDCFile(m_hw->dcDownloadFileName());
     if (ba.size() > 0) {