diff --git a/SrcPony/at90sxx.cpp b/SrcPony/at90sxx.cpp
index 08204cb..02c4c5e 100644
--- a/SrcPony/at90sxx.cpp
+++ b/SrcPony/at90sxx.cpp
@@ -395,8 +395,8 @@ int At90sxx::QueryType(long &type)
 			detected_type = type;
 		}
 
-		detected_signature.sprintf("%02X-%02X-%02X", code[0], code[1], code[2]);
 		//snprintf(detected_signature, MAXMSG, "%02X-%02X-%02X", code[0], code[1], code[2]);
+		detected_signature = QString("%1-%2-%3").arg(code[0], 2, 16, QLatin1Char('0')).arg(code[1], 2, 16, QLatin1Char('0')).arg(code[2], 2, 16, QLatin1Char('0'));
 
 		rv = type ? OK : DEVICE_UNKNOWN;
 	}
diff --git a/SrcPony/bitfield.cpp b/SrcPony/bitfield.cpp
index 4838a36..964ec12 100644
--- a/SrcPony/bitfield.cpp
+++ b/SrcPony/bitfield.cpp
@@ -74,7 +74,7 @@ void BitFieldWidget::initWidget()
 			int bitOffset = vecInfo->at(i).bit;
 			lastBit = bitOffset;
 			QString sDes = vecInfo->at(i).ShortDescr;
-			itm->setText(0, QString().sprintf("Bit %d, ", bitOffset) + sDes);
+			itm->setText(0, QString("Bit %1, ").arg(bitOffset) + sDes);
 			if (vecInfo->at(i).LongDescr.length() > 0)
 			{
 				itm->setText(1, vecInfo->at(i).LongDescr);
@@ -309,7 +309,7 @@ void BitFieldWidget::setMaskBits(const QString &cMask)
 	// at begin of string only
 	mskName = "^" + mskName + "\\d+";
 
-	qDebug() << cMask <<  "converted to" << mskName << (bin) << localField << (Qt::dec);
+	qDebug() << cMask <<  "converted to" << mskName << (Qt::bin) << localField << (Qt::dec);
 
 	// search in QTreeWidget the names
 	for (idx = 0; idx < treeWidget->topLevelItemCount(); idx++)
diff --git a/SrcPony/blockmdlg.cpp b/SrcPony/blockmdlg.cpp
index 662d439..390ae1e 100644
--- a/SrcPony/blockmdlg.cpp
+++ b/SrcPony/blockmdlg.cpp
@@ -56,9 +56,9 @@ blockDialog::blockDialog(e2CmdWindow *bw, e2AppWinInfo *p, bool readonly, const
 	lblTo->setText(translate(STR_MSGNUMBLOCK));
 	lblVal->setText(translate(STR_MSGHIGHENDBLK));
 
-	QString str1 = QString().sprintf("%d", (int)((lock >> 4) & 0x0F));
-	QString str2 = QString().sprintf("%d", (int)(lock & 0x0F));
-	QString str3 = QString().sprintf("%d", (int)(fuse & 0x0F));
+	QString str1 = QString("%1").arg((int)((lock >> 4) & 0x0F));	//sprintf("%d", (int)((lock >> 4) & 0x0F));
+	QString str2 = QString("%1").arg((int)(lock & 0x0F));	//sprintf("%d", (int)(lock & 0x0F));
+	QString str3 = QString("%1").arg((int)(fuse & 0x0F));	//sprintf("%d", (int)(fuse & 0x0F));
 
 	txiFrom->setText(str1);
 	txiTo->setText(str2);
diff --git a/SrcPony/e2awinfo.cpp b/SrcPony/e2awinfo.cpp
index 108a8f0..57a2288 100644
--- a/SrcPony/e2awinfo.cpp
+++ b/SrcPony/e2awinfo.cpp
@@ -1346,6 +1346,8 @@ QString e2AppWinInfo::Dump(int line, int type)
 {
 	long idx;
 	long upperlimit;
+	char lbuf[LINEBUF_SIZE + 1];
+	char tmpbuf[16 + 1];
 
 	if (!buf_ok)
 	{
@@ -1360,17 +1362,13 @@ QString e2AppWinInfo::Dump(int line, int type)
 	{
 		if (type == 0)
 		{
-			char tmpbuf[16 + 1];
-
 			for (int k = 0; k < hex_per_line; k++)
 			{
 				tmpbuf[k] = isprint(buffer[idx + k]) ? buffer[idx + k] : '.';
 			}
-
 			tmpbuf[hex_per_line] = 0;
 
-			linebuf.sprintf("  %06lX) %02X %02X %02X %02X %02X %02X %02X %02X - %02X %02X %02X %02X %02X %02X %02X %02X    %s\n",
-							//                      snprintf(linebuf, LINEBUF_SIZE, "  %06lX) %02X %02X %02X %02X %02X %02X %02X %02X - %02X %02X %02X %02X %02X %02X %02X %02X    %s\n",
+			snprintf(lbuf, LINEBUF_SIZE, "  %06lX) %02X %02X %02X %02X %02X %02X %02X %02X - %02X %02X %02X %02X %02X %02X %02X %02X    %s\n",
 							idx,
 							buffer[idx + 0],
 							buffer[idx + 1],
@@ -1395,13 +1393,11 @@ QString e2AppWinInfo::Dump(int line, int type)
 		}
 		else if (type == 1)
 		{
-			linebuf.sprintf("  %06lX)",     idx);
-			//                      snprintf(linebuf, LINEBUF_SIZE, "  %06lX)",     idx);
+			snprintf(lbuf, LINEBUF_SIZE, "  %06lX)", idx);
 		}
 		else if (type == 2)
 		{
-			linebuf.sprintf(" %02X %02X %02X %02X %02X %02X %02X %02X - %02X %02X %02X %02X %02X %02X %02X %02X  ",
-							//                      snprintf(linebuf, LINEBUF_SIZE, " %02X %02X %02X %02X %02X %02X %02X %02X - %02X %02X %02X %02X %02X %02X %02X %02X  ",
+			snprintf(lbuf, LINEBUF_SIZE, " %02X %02X %02X %02X %02X %02X %02X %02X - %02X %02X %02X %02X %02X %02X %02X %02X  ",
 							buffer[idx + 0],
 							buffer[idx + 1],
 							buffer[idx + 2],
@@ -1423,21 +1419,20 @@ QString e2AppWinInfo::Dump(int line, int type)
 		}
 		else
 		{
-			char tmpbuf[16 + 1];
-
 			for (int k = 0; k < hex_per_line; k++)
 			{
 				tmpbuf[k] = isprint(buffer[idx + k]) ? buffer[idx + k] : '.';
 			}
-
 			tmpbuf[hex_per_line] = 0;
 
-			linebuf.sprintf("  %s\n", tmpbuf);
-			//                      snprintf(linebuf, LINEBUF_SIZE, "  %s\n", tmpbuf);
+			snprintf(lbuf, LINEBUF_SIZE, "  %s\n", tmpbuf);
 		}
 
-		//              linebuf[LINEBUF_SIZE - 1] = '\0';
+		lbuf[LINEBUF_SIZE] = '\0';
+		return QString(lbuf);
+	}
+	else
+	{
+		return "";
 	}
-
-	return linebuf;
 }
diff --git a/SrcPony/e2cmdw.cpp b/SrcPony/e2cmdw.cpp
index 0b6304e..8aaf6c5 100644
--- a/SrcPony/e2cmdw.cpp
+++ b/SrcPony/e2cmdw.cpp
@@ -63,7 +63,7 @@
 
 
 #define STATUSBAR_FORM  "    Size     0 Bytes     CRC  0000h      "
-#define STATUSBAR_PRINT "    Size %5ld Bytes     CRC  %04Xh     %c"
+//#define STATUSBAR_PRINT "    Size %5ld Bytes     CRC  %04Xh     %c"
 
 
 class e2AppWinInfo;
@@ -118,12 +118,12 @@ e2CmdWindow::e2CmdWindow(QWidget *parent) :
 	// to check this
 	fontSize = E2Profile::GetFontSize();	//sysFont.pointSize();
 
-	programStyleSheet = QString().sprintf("font-size: %dpt", fontSize);
+	programStyleSheet = QString("font-size: %1pt").arg(fontSize);	//sprintf("font-size: %dpt", fontSize);
 
 	if (fontSize == -1)
 	{
 		fontSize = sysFont.pixelSize();
-		programStyleSheet = QString().sprintf("font-size: %dpx", fontSize);
+		programStyleSheet = QString("font-size: %1px").arg(fontSize);	//sprintf("font-size: %dpx", fontSize);
 	}
 
 	if (programStyleSheet.length() > 0)
@@ -1464,20 +1464,19 @@ void e2CmdWindow::selectFontSize(QAction *mnu)
 	// for lang menu and for fontsize menu
 	if (sz == -1)
 	{
-		programStyleSheet = QString().sprintf("font-size: %dpx", fontSize);
+		programStyleSheet = QString("font-size: %1px").arg(fontSize);	//sprintf("font-size: %dpx", fontSize);
 	}
 	else
 	{
-		programStyleSheet = QString().sprintf("font-size: %dpt", fontSize);
+		programStyleSheet = QString("font-size: %dpt").arg(fontSize);	//sprintf("font-size: %dpt", fontSize);
 	}
 
 	E2Profile::SetFontSize(fontSize);
 
-	QString sSheet2 = QString("QMenu { %1; }").arg(programStyleSheet);
-
 	setStyleSheet(programStyleSheet);
 
-	//     langMenu->setStyleSheet(sSheet2);
+	//QString sSheet2 = QString("QMenu { %1; }").arg(programStyleSheet);
+	//langMenu->setStyleSheet(sSheet2);
 
 	setFontForWidgets();
 }
@@ -2912,7 +2911,7 @@ int e2CmdWindow::CmdReadCalibration(int idx)
 				if (verbose == verboseAll)
 				{
 					QString str;
-					str = translate(STR_MSGREADCALIBOK) + QString().sprintf(": 0x%02X (%d)", rval, rval);
+					str = translate(STR_MSGREADCALIBOK) + QString(": 0x%1 (%2)").arg(rval, 2, 16, QLatin1Char('0')).arg(rval);		//sprintf(": 0x%02X (%d)", rval, rval);
 
 					QMessageBox note(QMessageBox::Information, "Calibration", str, QMessageBox::Ok);
 					note.setStyleSheet(programStyleSheet);
@@ -3190,7 +3189,7 @@ int e2CmdWindow::CmdProgram()
 		if (verbose != verboseNo)
 		{
 			QString str;
-			str = translate(STR_MSGPROGRAMFAIL) + QString().sprintf(" (%d)", result);
+			str = translate(STR_MSGPROGRAMFAIL) + QString(" (%1)").arg(result);	//sprintf(" (%d)", result);
 
 			QMessageBox note(QMessageBox::Critical, "Program", str, QMessageBox::Close);
 			note.setStyleSheet(programStyleSheet);
@@ -4333,7 +4332,7 @@ int e2CmdWindow::CmdRunScript(bool test_mode)
 		if (verbose != verboseNo)
 		{
 			QString str;
-			str = translate(STR_MSGPROGRAMFAIL) + QString().sprintf(" (%d)", result);
+			str = translate(STR_MSGPROGRAMFAIL) + QString(" (%1)").arg(result);	//sprintf(" (%d)", result);
 
 			QMessageBox note(QMessageBox::Critical, "Script information", str, QMessageBox::Close);
 			note.setStyleSheet(programStyleSheet);
@@ -5278,7 +5277,8 @@ void e2CmdWindow::UpdateStatusBar()
 	if (awip)
 	{
 		QString buf;
-		buf.sprintf(STATUSBAR_PRINT, GetDevSize(), awip->GetCRC(), awip->IsBufChanged() ? '*' : ' ');
+		//buf.sprintf(STATUSBAR_PRINT, GetDevSize(), awip->GetCRC(), awip->IsBufChanged() ? '*' : ' ');
+		buf = QString("    Size %1 Bytes     CRC  %2h     %3").arg(GetDevSize(), 5).arg(awip->GetCRC(), 4, 16, QLatin1Char('0')).arg(awip->IsBufChanged() ? '*' : ' ');
 		lblEEPInfo->setText(buf);
 		lblStringID->setText(awip->GetStringID());
 	}
@@ -6481,7 +6481,7 @@ void e2CmdWindow::Print()
 			t << QString("File: " + GetFileName());
 			t << QString("Device: " + awip->GetStringID());
 			t << QString("Note: " + awip->GetComment());
-			t << QString().sprintf("Size  : %ld Bytes    CRC: %04X", GetDevSize(), awip->GetCRC());
+			t << QString("Size  : %1 Bytes    CRC: %2h").arg(GetDevSize()).arg(awip->GetCRC(), 4, 16, QLatin1Char('0'));	//sprintf("Size  : %ld Bytes    CRC: %04X", GetDevSize(), awip->GetCRC());
 
 			for (; k < no_line && curRow < 66; k++)
 			{
@@ -6501,7 +6501,7 @@ void e2CmdWindow::Print()
 
 			doc.documentLayout()->setPaintDevice(&printer);
 
-			doc.setPageSize(printer.pageRect().size()); // This is necessary if you want to hide the page number
+			//doc.setPageSize(printer.pageRect().size()); // This is necessary if you want to hide the page number
 			doc.setHtml(str);
 			doc.print(&printer);
 		}
diff --git a/SrcPony/e2profil.cpp b/SrcPony/e2profil.cpp
index 7d2a771..8ea7a81 100644
--- a/SrcPony/e2profil.cpp
+++ b/SrcPony/e2profil.cpp
@@ -211,7 +211,7 @@ QStringList E2Profile::GetLastFiles()
 
 	for (int i = 0; i < 8; i++)
 	{
-		QString sp = s->value(QString().sprintf("LastFile%d", i), "").toString();
+		QString sp = s->value(QString("LastFile%1").arg(i), "").toString();
 		if (sp.length() == 0)
 		{
 			break;
@@ -228,12 +228,12 @@ void E2Profile::SetLastFiles(const QStringList &l)
 
 	foreach (QString t, l)
 	{
-		s->setValue(QString().sprintf("LastFile%d", i), t);
+		s->setValue(QString("LastFile%1").arg(i), t);
 		i++;
 	}
 //	for (; i < 8; i++)
 //	{
-//		s->setValue(QString().sprintf("LastFile%d", i), "");
+//		s->setValue(QString("LastFile%1").arg(i), "");
 //	}
 }
 
@@ -243,7 +243,7 @@ QStringList E2Profile::GetLastScripts()
 
 	for (int i = 0; i < 8; i++)
 	{
-		QString sp = s->value(QString().sprintf("LastScript%d", i), "").toString();
+		QString sp = s->value(QString("LastScript%1").arg(i), "").toString();
 		res << sp;
 	}
 
@@ -256,12 +256,12 @@ void E2Profile::SetLastScripts(const QStringList &l)
 
 	foreach (QString t, l)
 	{
-		s->setValue(QString().sprintf("LastScript%d", i), t);
+		s->setValue(QString("LastScript%1").arg(i), t);
 		i++;
 	}
 	for (; i < 8; i++)
 	{
-		s->setValue(QString().sprintf("LastFile%d", i), "");
+		s->setValue(QString("LastFile%1").arg(i), "");
 	}
 }
 
@@ -329,7 +329,7 @@ void E2Profile::SetI2CBaseAddr(int base_addr)
 {
 	if (base_addr >= 0x00 && base_addr < 0x100)
 	{
-		s->setValue("I2CBaseAddress", QString().sprintf("0x%X", base_addr));
+		s->setValue("I2CBaseAddress", QString("0x%1").arg(base_addr, 0, 16));
 	}
 }
 
@@ -532,21 +532,21 @@ void E2Profile::GetPrinterSettings(QPrinter &p)
 	s->beginGroup("Printer");
 
 	p.setPrinterName(s->value("PrinterName").toString());
-	p.setPageSize(QPrinter::PaperSize(s->value("PageSize", QPrinter::A4).toInt()));
+	p.setPageSize(QPageSize(QPageSize::PageSizeId(s->value("PageSize", QPageSize::A4).toInt())));
 	p.setCollateCopies(s->value("Copies", false).toBool());
 	p.setColorMode(QPrinter::ColorMode(s->value("ColorMode").toInt()));
 	p.setCopyCount(s->value("CopyCount", 1).toInt());
 	p.setCreator(s->value("Creator", "").toString());
 	p.setDocName(s->value("DocName",  "ponyprog.pdf").toString());
-	p.setDoubleSidedPrinting(s->value("DoubleSide", false).toBool());
+	//p.setDoubleSidedPrinting(s->value("DoubleSide", false).toBool());
 	p.setDuplex(QPrinter::DuplexMode(s->value("Duplex").toInt()));
 	p.setFontEmbeddingEnabled(s->value("FontEmb", false).toBool());
 	p.setFullPage(s->value("FullPage", false).toBool());
-	p.setOrientation(QPrinter::Orientation(s->value("Orientation", QPrinter::Portrait).toInt()));
+	p.setPageOrientation(QPageLayout::Orientation(s->value("Orientation", QPageLayout::Portrait).toInt()));
 	p.setOutputFileName(s->value("OutputName", "").toString());
 	p.setOutputFormat(QPrinter::OutputFormat(s->value("OutputFormat", QPrinter::PdfFormat).toInt()));
 	p.setPageOrder(QPrinter::PageOrder(s->value("PageOrder").toInt()));
-	p.setPaperSize(QPrinter::PaperSize(s->value("PaperSize").toInt()));
+	//p.setPaperSize(QPrinter::PaperSize(s->value("PaperSize").toInt()));
 	p.setPaperSource(QPrinter::PaperSource(s->value("PaperSource").toInt()));
 	p.setPrintProgram(s->value("PrintProg", "").toString());
 	p.setPrintRange(QPrinter::PrintRange(s->value("PrintRange").toInt()));
@@ -557,8 +557,7 @@ void E2Profile::GetPrinterSettings(QPrinter &p)
 	top = (s->value("TopMargin", 15).toFloat());
 	right = (s->value("RightMargin", 15).toFloat());
 	bottom = (s->value("BottomMargin", 15).toFloat());
-
-	p.setPageMargins(left, top, right, bottom, QPrinter::Millimeter);
+	p.setPageMargins(QMarginsF(left, top, right, bottom), QPageLayout::Unit::Millimeter);
 
 	s->endGroup();
 }
@@ -568,33 +567,31 @@ void E2Profile::SetPrinterSettings(QPrinter &p)
 	s->beginGroup("Printer");
 
 	s->setValue("PrinterName", p.printerName());
-	s->setValue("PageSize", p.pageSize());
+	s->setValue("PageSize", p.pageLayout().pageSize().id());
 	s->setValue("Copies", p.collateCopies());
 	s->setValue("ColorMode", p.colorMode());
 	s->setValue("CopyCount", p.copyCount());
 	s->setValue("Creator", p.creator());
 	s->setValue("DocName", p.docName());
-	s->setValue("DoubleSide", p.doubleSidedPrinting());
+	//s->setValue("DoubleSide", p.doubleSidedPrinting());
 	s->setValue("Duplex", p.duplex());
 	s->setValue("FontEmb", p.fontEmbeddingEnabled());
 	s->setValue("FullPage", p.fullPage());
-	s->setValue("Orientation", p.orientation());
+	s->setValue("Orientation", p.pageLayout().orientation());
 	s->setValue("OutputName", p.outputFileName());
 	s->setValue("OutputFormat", p.outputFormat());
 	s->setValue("PageOrder", p.pageOrder());
-	s->setValue("PaperSize", p.paperSize());
+	//s->setValue("PaperSize", p.paperSize());
 	s->setValue("PaperSource", p.paperSource());
 	s->setValue("PrintProg", p.printProgram());
 	s->setValue("PrintRange", p.printRange());
 	s->setValue("Resolution", p.resolution());
 
-	qreal left, top, right, bottom;
-	p.getPageMargins(&left, &top, &right, &bottom, QPrinter::Millimeter);
-
-	s->setValue("LeftMargin", left);
-	s->setValue("TopMargin", top);
-	s->setValue("BottomMargin", bottom);
-	s->setValue("RightMargin", right);
+	QMarginsF qmf(p.pageLayout().margins());
+	s->setValue("LeftMargin", qmf.left());
+	s->setValue("TopMargin", qmf.top());
+	s->setValue("BottomMargin", qmf.bottom());
+	s->setValue("RightMargin", qmf.right());
 
 	s->endGroup();
 }
@@ -767,7 +764,7 @@ int E2Profile::GetSerialNumAddress(long &start, int &size, bool &mtype)
 void E2Profile::SetSerialNumAddress(unsigned long start, int size, bool mtype)
 {
 	s->beginGroup("SerialNumber");
-	s->setValue("Address", QString().sprintf("0x%04lX", start));
+	s->setValue("Address", QString("0x%1").arg(start, 4, 16, QLatin1Char('0')));		//sprintf("0x%04lX", start)
 
 	if (size >= 1)
 	{
@@ -1392,7 +1389,8 @@ void E2Profile::SetCalibrationAddress(bool enabled, unsigned long start, int siz
 {
 	s->beginGroup("OscillatorCalibration");
 	s->setValue("Enabled", enabled);
-	s->setValue("StartAddress", QString().sprintf("0x%04lX", start));
+	s->setValue("StartAddress", QString("0x%1").arg(start, 4, 16, QLatin1Char('0')));	//sprintf("0x%04lX", start)
+
 	if (size >= 1)
 	{
 		s->setValue("Size", size);
@@ -1459,27 +1457,21 @@ void E2Profile::SetCOMAddress(unsigned int com1, unsigned int com2, unsigned int
 
 	if (com1 > 0)
 	{
+		str = QString("%1").arg(com1, 0, 16);
+
 		if (com2 > 0)
 		{
+			str += QString(",%1").arg(com2, 0, 16);
+
 			if (com3 > 0)
 			{
+				str += QString(",%1").arg(com3, 0, 16);
+
 				if (com4 > 0)
 				{
-					str.sprintf("%X,%X,%X,%X", com1, com2, com3, com4);
-				}
-				else
-				{
-					str.sprintf("%X,%X,%X", com1, com2, com3);
+					str += QString(",%1").arg(com4, 0, 16);
 				}
 			}
-			else
-			{
-				str.sprintf("%X,%X", com1, com2);
-			}
-		}
-		else
-		{
-			str.sprintf("%X", com1);
 		}
 
 		s->setValue("LegacyPorts/COMPorts", str);
@@ -1509,20 +1501,16 @@ void E2Profile::SetLPTAddress(unsigned int lpt1, unsigned int lpt2, unsigned int
 
 	if (lpt1 > 0)
 	{
+		str = QString("%1").arg(lpt1, 0, 16);
+
 		if (lpt2 > 0)
 		{
+			str += QString(",%1").arg(lpt2, 0, 16);
+
 			if (lpt3 > 0)
 			{
-				str.sprintf("%X,%X,%X", lpt1, lpt2, lpt3);
+				str += QString(",%1").arg(lpt3, 0, 16);
 			}
-			else
-			{
-				str.sprintf("%X,%X", lpt1, lpt2);
-			}
-		}
-		else
-		{
-			str.sprintf("%X", lpt1);
 		}
 
 		s->setValue("LegacyPorts/LPTPorts", str);
diff --git a/SrcPony/filldlg.cpp b/SrcPony/filldlg.cpp
index c0b8048..8d390bc 100644
--- a/SrcPony/filldlg.cpp
+++ b/SrcPony/filldlg.cpp
@@ -68,13 +68,13 @@ FillDialog::FillDialog(QWidget *bw, long &cfrom, long &cto, int &cval, long max_
 
 	//TODO: should get strings from E2Profile settings, not local variables
 	QString str;
-	str = QString().sprintf("0x%04lX", mFrom);
+	str = QString("0x%1").arg(mFrom, 4, 16, QLatin1Char('0'));	//sprintf("0x%04lX", mFrom);
 	txiFrom->setText(str);
 
-	str = QString().sprintf("0x%04lX", mTo);
+	str = QString("0x%1").arg(mTo, 4, 16, QLatin1Char('0'));	//sprintf("0x%04lX", mTo);
 	txiTo->setText(str);
 
-	str = QString().sprintf("0x%02X", mVal);
+	str = QString("0x%1").arg(mVal, 2, 16, QLatin1Char('0'));	//sprintf("0x%02X", mVal);
 	txiVal->setText(str);
 
 	connect(pushOk, SIGNAL(clicked()), this, SLOT(onOk()));
diff --git a/SrcPony/fusemdlg.cpp b/SrcPony/fusemdlg.cpp
index 8b315de..b38a562 100644
--- a/SrcPony/fusemdlg.cpp
+++ b/SrcPony/fusemdlg.cpp
@@ -235,11 +235,11 @@ void fuseModalDialog::displayBitFields()
 	QString s;
 	if (fuseEnabled == true)
 	{
-		s = QString().sprintf("Fuse: 0x%08X  ", fuseBits);
+		s = QString("Fuse: 0x%1  ").arg(fuseBits, 8, 16, QLatin1Char('0'));	//sprintf("Fuse: 0x%08X  ", fuseBits);
 	}
 	if (lockEnabled == true)
 	{
-		s +=  QString().sprintf("Lock: 0x%08X", lockBits);
+		s += QString("Lock: 0x%1").arg(lockBits, 8, 16, QLatin1Char('0'));	//sprintf("Lock: 0x%08X", lockBits);
 	}
 	labelFuseLock->setText(s);
 }
diff --git a/SrcPony/infomdlg.cpp b/SrcPony/infomdlg.cpp
index e77b76c..90baa44 100644
--- a/SrcPony/infomdlg.cpp
+++ b/SrcPony/infomdlg.cpp
@@ -67,11 +67,11 @@ e24xx_infoModalDialog::e24xx_infoModalDialog(QWidget *bw, int rlv, uint16_t crc,
 	lblVal->setText(translate(STR_MSGFLASHSIZE)); // flash size label
 
 	QString str;
-	str = QString().sprintf("%04Xh", crc);
+	str = QString("%1h").arg(crc, 4, 16, QLatin1Char('0'));	//sprintf("%04Xh", crc);
 	txiTo->setText(str);
 	txiTo->setReadOnly(true);
 
-	str = QString().sprintf("%ld Byte", size);
+	str = QString("%1 Byte").arg(size);	//sprintf("%ld Byte", size);
 	txiVal->setText(str);
 	txiVal->setReadOnly(true);
 
@@ -118,15 +118,15 @@ other_infoModalDialog::other_infoModalDialog(QWidget *bw, long fsize, long esize
 	lblTo->setText(translate(STR_MSGEEPSIZE)); // size label
 	lblVal->setText(translate(STR_MSGFLASHSIZE)); // flash size label
 
-	str = QString().sprintf("%04Xh", crc);
+	str = QString("%1h").arg(crc, 4, 16, QLatin1Char('0'));	//sprintf("%04Xh", crc);
 	txiFrom->setText(str);
 	txiFrom->setReadOnly(true);
 
-	str = QString().sprintf("%ld Byte", fsize);
+	str = QString("%1 Byte").arg(fsize);	//sprintf("%ld Byte", fsize);
 	txiTo->setText(str);
 	txiTo->setReadOnly(true);
 
-	str = QString().sprintf("%ld Byte", esize);
+	str = QString("%1 Byte").arg(esize);	//sprintf("%ld Byte", esize);
 	txiVal->setText(str);
 	txiVal->setReadOnly(true);
 
diff --git a/SrcPony/intfbuf.cpp b/SrcPony/intfbuf.cpp
index a8c2226..07dea85 100644
--- a/SrcPony/intfbuf.cpp
+++ b/SrcPony/intfbuf.cpp
@@ -92,28 +92,26 @@ int IntelFileBuf::WriteRecord(QFile &fh, uint8_t *bptr, long curaddr, long recsi
 		int len = recsize;
 		QTextStream out(&fh);
 
-		out << ":";
-
-		//byte count
-		out << QString().sprintf("%02X", len & 0xFF);
+		//start + byte count
+		out << QString(":%1").arg(len & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X", len & 0xFF)
 		checksum += len & 0xFF;
 
 		//addr field
-		out << QString().sprintf("%04lX", curaddr & 0xFFFF);
+		out << QString("%1").arg(curaddr & 0xFFFF, 4, 16, QLatin1Char('0'));	//sprintf("%04lX", curaddr & 0xFFFF);
 		checksum += (curaddr >> 8) & 0xFF;
 		checksum += curaddr & 0xFF;
 
 		//record type
-		out << QString().sprintf("%02X", fmt & 0xFF);
+		out << QString("%1").arg(fmt & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X", fmt & 0xFF);
 		checksum += fmt & 0xFF;
 
 		for (j = 0; j < recsize; j++)
 		{
-			out << QString().sprintf("%02X", bptr[curaddr + j]);
+			out << QString("%1").arg(bptr[curaddr + j], 2, 16, QLatin1Char('0'));	//sprintf("%02X", bptr[curaddr + j]);
 			checksum += bptr[curaddr + j];
 		}
 
-		out << QString().sprintf("%02X\n", (~checksum + 1) & 0xFF);
+		out << QString("%1\n").arg((~checksum + 1) & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X\n", (~checksum + 1) & 0xFF);
 	}
 
 	return rval;
@@ -124,22 +122,20 @@ int IntelFileBuf::WriteAddressRecord(QFile &fh, long curaddr, bool linear_addres
 	int rval = 1;
 	QTextStream out(&fh);
 
-	out << ":";
-
 	int checksum = 0;
 	int len = 2;
 
-	//byte count
-	out << QString().sprintf("%02X", len & 0xFF);
+	//start + byte count
+	out << QString(":%1").arg(len & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X", len & 0xFF);
 	checksum += len & 0xFF;
 
 	//addr field
-	out << QString().sprintf("%04X", 0);
+	out << QString("0000");	//sprintf("%04X", 0);
 
 	if (linear_address)
 	{
 		//record type
-		out << QString().sprintf("%02X", LIN_ADDR_RECORD & 0xFF);
+		out << QString("%1").arg(LIN_ADDR_RECORD & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X", LIN_ADDR_RECORD & 0xFF);
 		checksum += LIN_ADDR_RECORD & 0xFF;
 
 		//adjust extended linear address
@@ -148,18 +144,18 @@ int IntelFileBuf::WriteAddressRecord(QFile &fh, long curaddr, bool linear_addres
 	else
 	{
 		//record type
-		out << QString().sprintf("%02X", SEG_ADDR_RECORD & 0xFF);
+		out << QString("%1").arg(SEG_ADDR_RECORD & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X", SEG_ADDR_RECORD & 0xFF);
 		checksum += SEG_ADDR_RECORD & 0xFF;
 
 		//adjust extended segmented address
 		curaddr >>= 4;
 	}
 
-	out << QString().sprintf("%04lX", curaddr & 0xFFFF);
+	out << QString("%1").arg(curaddr & 0xFFFF, 4, 16, QLatin1Char('0'));	//sprintf("%04lX", curaddr & 0xFFFF);
 	checksum += (curaddr >> 8) & 0xFF;
 	checksum += curaddr & 0xFF;
 
-	out << QString().sprintf("%02X\n", (~checksum + 1) & 0xFF);
+	out << QString("%1\n").arg((~checksum + 1) & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X\n", (~checksum + 1) & 0xFF);
 
 	return rval;
 }
diff --git a/SrcPony/linuxsysfsint.cpp b/SrcPony/linuxsysfsint.cpp
index 2b0662f..0ecfcfc 100644
--- a/SrcPony/linuxsysfsint.cpp
+++ b/SrcPony/linuxsysfsint.cpp
@@ -69,7 +69,8 @@ static int gpio_open(unsigned int gpio, bool out_dir)
 	int rval;
 
 	//trying with gpio command (you need wiringPi installed)
-	buf.sprintf("export %u %s", gpio, out_dir ? "out" : "in");
+	//buf.sprintf("export %u %s", gpio, out_dir ? "out" : "in");
+	buf = QString("export %1 ").arg(gpio) + QString(out_dir ? "out" : "in");
 // 	rval = system(buf.toLatin1().data());
 	rval = QProcess::execute("gpio", buf.split(" "));
 
@@ -97,7 +98,8 @@ static int gpio_open(unsigned int gpio, bool out_dir)
 
 		if (rval == 0)
 		{
-			buf.sprintf("%s/gpio%d/direction", SYSFS_GPIO_DIR, gpio);
+			//buf.sprintf("%s/gpio%d/direction", SYSFS_GPIO_DIR, gpio);
+			buf = QString(SYSFS_GPIO_DIR) + QString("/gpio%1/direction").arg(gpio);
 			fd = open(buf.toLatin1().data(), O_WRONLY);
 
 			if (fd < 0)
@@ -131,7 +133,8 @@ static int gpio_open(unsigned int gpio, bool out_dir)
 	{
 		int fd;
 
-		buf.sprintf("%s/gpio%d/value", SYSFS_GPIO_DIR, gpio);
+		//buf.sprintf("%s/gpio%d/value", SYSFS_GPIO_DIR, gpio);
+		buf = QString(SYSFS_GPIO_DIR) + QString("/gpio%1/value").arg(gpio);
 		fd = open(buf.toLatin1().data(), out_dir ? O_WRONLY : O_RDONLY);
 
 		if (fd < 0)
@@ -163,7 +166,8 @@ static int gpio_close(unsigned int gpio, int fd)
 	}
 
 	//trying with gpio command (you need wiringPi installed)
-	buf.sprintf("unexport %u", gpio);
+	//buf.sprintf("unexport %u", gpio);
+	buf = QString("unexport %1").arg(gpio);
 // 	rval = system(buf.toLatin1().data());
 	rval = QProcess::execute("gpio", buf.split(" "));
 
diff --git a/SrcPony/motsfbuf.cpp b/SrcPony/motsfbuf.cpp
index 07f51e1..e76dfbf 100644
--- a/SrcPony/motsfbuf.cpp
+++ b/SrcPony/motsfbuf.cpp
@@ -142,23 +142,23 @@ int MotorolaSFileBuf::WriteRecord(QTextStream &outs, uint8_t *bptr, long curaddr
 		int checksum = 0;
 
 		//type field
-		outs << QString().sprintf("S%c", fmt);
+		outs << QString("S%1").arg(QLatin1Char(fmt));	//sprintf("S%c", fmt);
 
 		//len field
-		outs << QString().sprintf("%02X", len & 0xFF);
+		outs << QString("%1").arg(len & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X", len & 0xFF);
 		checksum += len & 0xFF;
 
 		//addr field
 		if (fmt == DATA_RECORD24 || fmt == END_RECORD24)
 		{
-			outs << QString().sprintf("%06lX", curaddr & 0xFFFFFF);
+			outs << QString("%1").arg(curaddr & 0xFFFFFF, 6, 16, QLatin1Char('0'));	//sprintf("%06lX", curaddr & 0xFFFFFF);
 			checksum += (curaddr >> 16) & 0xFF;
 			checksum += (curaddr >> 8) & 0xFF;
 			checksum += curaddr & 0xFF;
 		}
 		else if (fmt == DATA_RECORD32 || fmt == END_RECORD32)
 		{
-			outs << QString().sprintf("%08lX", curaddr);
+			outs << QString("%1").arg(curaddr, 8, 16, QLatin1Char('0'));	//sprintf("%08lX", curaddr);
 			checksum += (curaddr >> 24) & 0xFF;
 			checksum += (curaddr >> 16) & 0xFF;
 			checksum += (curaddr >> 8) & 0xFF;
@@ -166,18 +166,18 @@ int MotorolaSFileBuf::WriteRecord(QTextStream &outs, uint8_t *bptr, long curaddr
 		}
 		else        //all other have a 16 bit address field
 		{
-			outs << QString().sprintf("%04lX", curaddr & 0xFFFF);
+			outs << QString("%1").arg(curaddr & 0xFFFF, 4, 16, QLatin1Char('0'));	//sprintf("%04lX", curaddr & 0xFFFF);
 			checksum += (curaddr >> 8) & 0xFF;
 			checksum += curaddr & 0xFF;
 		}
 
 		for (j = 0; j < recsize; j++)
 		{
-			outs << QString().sprintf("%02X", bptr[curaddr + j]);
+			outs << QString("%1").arg(bptr[curaddr + j], 2, 16, QLatin1Char('0'));	//sprintf("%02X", bptr[curaddr + j]);
 			checksum += bptr[curaddr + j];
 		}
 
-		outs << QString().sprintf("%02X\n", ~checksum & 0xFF);
+		outs << QString("%1\n").arg(~checksum & 0xFF, 2, 16, QLatin1Char('0'));	//sprintf("%02X\n", ~checksum & 0xFF);
 	}
 
 	return rval;
diff --git a/SrcPony/sernumdlg.cpp b/SrcPony/sernumdlg.cpp
index 83b7f90..9f756a0 100644
--- a/SrcPony/sernumdlg.cpp
+++ b/SrcPony/sernumdlg.cpp
@@ -60,9 +60,9 @@ SerNumDialog::SerNumDialog(QWidget *bw, const QString title) :
 		size = 4;
 	}
 
-	txiLoc->setText(QString().sprintf("0x%04lX", loc));
-	txiLen->setText(QString().sprintf("%d", size));
-	txiVal->setText(QString().sprintf("%lu", val));
+	txiLoc->setText(QString("0x%1").arg(loc, 4, 16, QLatin1Char('0')));	//sprintf("0x%04lX", loc));
+	txiLen->setText(QString("%1").arg(size));	//sprintf("%d", size));
+	txiVal->setText(QString("%1").arg(val));	//sprintf("%lu", val));
 
 	chkMemOffset->setChecked(memtype);
 	chkAutoInc->setChecked(autoinc);
@@ -204,8 +204,8 @@ OscCalibDialog::OscCalibDialog(QWidget *bw, e2AppWinInfo *aw, const QString titl
 
 	loc = (loc < 0) ? 0 : loc;
 
-	txiLoc->setText(QString().sprintf("0x%04lX", loc));
-	txiVal->setText(QString().sprintf("%d", val));
+	txiLoc->setText(QString("0x%1").arg(loc, 4, 16, QLatin1Char('0')));	//sprintf("0x%04lX", loc));
+	txiVal->setText(QString("%1").arg(val));	//sprintf("%d", val));
 
 	chkMemOffset->setChecked(memtype);
 	chkEnabled->setChecked(enabled);
@@ -272,7 +272,7 @@ void OscCalibDialog::onRead()
 	int val = awip->ReadOscCalibration();
 	if (val >= 0)
 	{
-		txiVal->setText(QString().sprintf("0x%02X", val));
+		txiVal->setText(QString("0x%1").arg(val, 2, 16, QLatin1Char('0')));	//sprintf("0x%02X", val));
 	}
 	else
 	{
diff --git a/ponyprog.pro b/ponyprog.pro
index 2451bc7..f46b5df 100644
--- a/ponyprog.pro
+++ b/ponyprog.pro
@@ -342,6 +342,7 @@ CONFIG(debug, debug|release) {
 
 # -Wall are already on the command line (where does it come from?)
 # for old GCC -std=c++11 move to -std=c++0x
+#QMAKE_CXXFLAGS += -flto=4 -Werror=odr -Werror=lto-type-mismatch -Werror=strict-aliasing
 QMAKE_CXXFLAGS += -Wno-unused-parameter
 
 unix: QMAKE_CXXFLAGS += -std=c++11