--- a/OSTC4Operations.cpp	Sun Nov 30 18:37:32 2025 +0100
+++ b/OSTC4Operations.cpp	Tue Dec 30 21:41:02 2025 +0100
@@ -38,6 +38,7 @@
 #include <QRegularExpression>
 #include "OSTC4Operations.h"
 
+
 #include "Utils/Log.h"
 #include "Utils/Exception.h"
 #include "Utils/ProgressEvent.h"
@@ -64,9 +65,21 @@
 
 HardwareOperations::CompanionFeatures OSTC4Operations::supported() const
 {
-    // No ICON, no DUMPSCREEN
-    return CompanionFeatures(PARAMETERS|DATE|NAME|FIRMWARE
-                     |HELIUM_DIVE|CCR_DIVE|BLUETOOTH|VPM_MODEL|SIGNAL_CHECK);
+    // No DUMPSCREEN
+
+    CompanionFeatures features;
+    features |= PARAMETERS;
+    features |= DATE;
+    features |= NAME;
+    features |= FIRMWARE;
+    features |= HELIUM_DIVE;
+    features |= CCR_DIVE;
+    features |= BLUETOOTH;
+    features |= VPM_MODEL;
+    features |= SIGNAL_CHECK;
+    features |= ICON;
+
+   return features;
 }
 
 QString OSTC4Operations::firmwareTemplate() const
@@ -188,6 +201,7 @@
   : fileChecksum(0,0)
 {
     emulatorName = "OSTC4/5";
+    m_crcWrapper = new CrcWrapper(nullptr);
 }
 
 //////////////////////////////////////////////////////////////////////////////
@@ -202,18 +216,131 @@
     LOG_INFO("Please wait for OSTC4/5 to complete installation...");
 }
 
+#define SWAP4BYTES(x)  \
+uint( (((x) & 0x000000FF) << 24)  \
+     | (((x) & 0x0000FF00) <<  8)  \
+     | (((x) & 0x00FF0000) >>  8)  \
+     | (((x) & 0xFF000000) >> 24))
+
+void OSTC4Operations::setIcons(const QString &fileName)
+{
+    int size;
+    int blockSize;
+    int transferDelay;
+    unsigned char echo;
+
+    FirmwareOSTC4 header;
+
+    unsigned char buf3offset[4];
+    unsigned char bufVersion[4];
+    uint32_t checksum = 0;
+    uint32_t width = 0;
+    uint32_t height = 0;
+
+    blockSize = FIRMWARE_BLOCK;
+    transferDelay = FIRMWARE_BLOCK_DELAY;
+
+    try
+    {
+        bmp = std::make_unique<BmpToArray>(fileName);
+    }
+    catch (const std::exception& e)
+    {
+        std::cerr << "Fehler beim Laden: " << e.what() << '\n';
+    }
+
+    QByteArray bin = bmp->getTransferBytes();
+    bmp->getImageXY(&width, &height);
+
+    if(bin.size() < 200000)
+    {
+        buf3offset[0] = 0x20;
+        buf3offset[1] = 0x00;
+        buf3offset[2] = 0x00;
+        buf3offset[3] = 0x00;
+        bufVersion[0] = 1;
+        bufVersion[1] = 0;
+        bufVersion[2] = 0;
+        bufVersion[3] = 0;
+
+        header.type = 0x20;
+        /* original header shallnot be modifieded => split image size information into 5 bytes */
+        header.dummy5 = width;          /* low byte */
+        header.dummy6 = height;         /* low byte */
+        header.dummy7 = (width >> 8) & 0x0000000F;  /* shifted high nibble */
+        header.dummy7 |= (height >> 4) & 0x000000F0; /* shifted high nibble */
+
+        header.length = SWAP4BYTES(bin.size());
+        header.checksum = bin.size() + (256*256*256*header.type) + (256*256* header.dummy5) + (256*header.dummy6) + header.dummy7;
+
+        checksum = SWAP4BYTES(m_crcWrapper->CRC_CalcBlockCRC(reinterpret_cast<uint32_t*>(bin.data()), bin.size() / 4));
+
+        //---- Upload icon -----------------------------------------------
+        const int steps = 3 + (bin.size()+blockSize-1) / blockSize;
+        int step = 0;
+        PROGRESS(step++, steps);
+
+        LOG_INFO(QString("    uploading icon size %1 bytes").arg(bin.size()));
+        writeText( QString("Upload Icon") );
+
+        //---- Command
+        PROGRESS(step++, steps);
+        echo = retryCommand(_serial, 'o'); // 0x6F upload icon
+        if( echo != 'o' )
+            LOG_THROW("Bad OSTC4/5 icon upload.");
+
+        //---- Header
+        PROGRESS(step++, steps);
+        _serial.writeBlock((uchar*)&header, sizeof header);
+        _serial.sleep(500);
+        //---- Data
+        for(int len = 0x00000; len < bin.size(); len += blockSize)
+        {
+            if(transferDelay)
+            {
+                _serial.sleep(transferDelay);  // 15 msec between 64B blocks...
+            }
+            PROGRESS(step++, steps);
+
+            size = qMin(blockSize,
+                        bin.size() - len);
+
+            LOG_TRACE("Fill " << size);
+            _serial.writeBlock((uchar*)bin.data()+len, (unsigned int)size);
+        }
+        _serial.writeBlock((uchar*)&checksum, 4);
+        PROGRESS(steps, steps); // 100%
+
+        //---- Wait acknowledge ----------------------------------------------
+        PROGRESS_THROTTLE();
+
+            for(int wait=0; wait<2*60; ++wait)  // Up to 2 min...
+            {
+                try {
+                    unsigned char reply = _serial.readByte();
+                    if( reply == 0x4D )
+                        break;
+                }
+                catch( const ReadTimeout&) {}
+            }
+
+        LOG_INFO("    icon uploaded.");
+    }
+    else
+    {
+        LOG_THROW("Image to large. Must be < 200k.");
+    }
+    PROGRESS_RESET();
+}
+
+
+
 //////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////
 ///     FIRMWARE UPGRADE                                                   ///
 //////////////////////////////////////////////////////////////////////////////
 //////////////////////////////////////////////////////////////////////////////
 
-#define SWAP4BYTES(x)  \
-    uint( (((x) & 0x000000FF) << 24)  \
-        | (((x) & 0x0000FF00) <<  8)  \
-        | (((x) & 0x00FF0000) >>  8)  \
-        | (((x) & 0xFF000000) >> 24))
-
 //////////////////////////////////////////////////////////////////////////////
 
 void OSTC4Operations::openFirmware(const QString &fileName, bool dryRun)