Various minor fixes

Fix some of the example programs
 - recursive is still broken

Replace text with logo in the about widget
 - also added an 128x128 variant

Don't allow empty memory to be exported

aboutwindow.cpp

@@ -1,12 +1,18 @@
 #include "aboutwindow.h"
 #include "ui_aboutwindow.h"
+#include <QIcon>
+#include <QPixmap>
 
 AboutWindow::AboutWindow(QWidget *parent) :
     QDialog(parent),
     ui(new Ui::AboutWindow)
 {
     ui->setupUi(this);
     connect(ui->okButton, &QPushButton::clicked, this, &QWidget::close);
+    // Load the icon
+    QIcon ico(":/bettertrn.ico");
+    // Get the 128x128 size
+    ui->iconLabel->setPixmap(ico.pixmap(128, 128));
 }
 
 AboutWindow::~AboutWindow()

aboutwindow.ui

@@ -49,16 +49,18 @@
     <enum>QLayout::SetDefaultConstraint</enum>
    </property>
    <item>
-    <widget class="QLabel" name="label">
-     <property name="font">
-      <font>
-       <pointsize>16</pointsize>
-       <weight>75</weight>
-       <bold>true</bold>
-      </font>
+    <widget class="QLabel" name="iconLabel">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Preferred" vsizetype="Maximum">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
      </property>
      <property name="text">
-      <string>BetterTRN</string>
+      <string/>
+     </property>
+     <property name="scaledContents">
+      <bool>false</bool>
      </property>
      <property name="alignment">
       <set>Qt::AlignCenter</set>

examples/recursive.asm

@@ -15,4 +15,5 @@ CPIA:	STI  TEMP
 TEMP:	RES 1
 DATA:	CON 2
 DATA2:	CON 32
-	RES 3
+	RES 3
+	END

examples/test.asm

@@ -1,10 +1,10 @@
 	NAM panos		
 	ORG 8
-LOC2	CON 	2,4
+LOC2:	CON 	2,4
 	ORG 0
 FIR: 	LDA	8
 	LDX	9
 	STA	9
 	STX	8
 	HLT
-	END
+	END

examples/test5.asm

@@ -1,5 +1,5 @@
-	INP
-	OUT
-	HLT
-
-  
+NAM loopback
+INP
+OUT
+HLT
+END

mainwindow.cpp

@@ -339,6 +339,11 @@ void MainWindow::emuThreadStopped()
 
 void MainWindow::on_actionSave_Memory_Image_triggered()
 {
+    if(pgmmem.isEmpty())
+    {
+        QMessageBox::warning(this, tr("Nothing in memory"), tr("There is nothing in memory. Please load a program first"));
+        return;
+    }
     QString path = QFileDialog::getSaveFileName(this, tr("Save Memory Image"), QString(), tr("Memory Image (*.mif)"));
     if(path.isEmpty())
         return;