diff --git a/src/cpu/x86_ops_flag.h b/src/cpu/x86_ops_flag.h
index 3da048dd5..16215b525 100644
--- a/src/cpu/x86_ops_flag.h
+++ b/src/cpu/x86_ops_flag.h
@@ -293,11 +293,11 @@ static int opPOPFD(uint32_t fetchdat)
         else if (IOPLp)           cpu_state.flags = (cpu_state.flags & 0x3000) | (templ & 0x4fd5) | 2;
         else                      cpu_state.flags = (cpu_state.flags & 0x3200) | (templ & 0x4dd5) | 2;
 
-        templ &= (is486) ? 0x3c0000 : 0;
+        templ &= (is486 || isibm486) ? 0x3c0000 : 0;
         templ |= ((cpu_state.eflags&3) << 16);
         if (cpu_CR4_mask & CR4_VME) cpu_state.eflags = (templ >> 16) & 0x3f;
         else if (CPUID)             cpu_state.eflags = (templ >> 16) & 0x27;
-        else if (is486) cpu_state.eflags = (templ >> 16) & 7;
+        else if (is486 || isibm486) cpu_state.eflags = (templ >> 16) & 7;
         else                        cpu_state.eflags = (templ >> 16) & 3;
 
         flags_extract();
diff --git a/src/mem/mem.c b/src/mem/mem.c
index ecda875a6..2aea1748f 100644
--- a/src/mem/mem.c
+++ b/src/mem/mem.c
@@ -302,7 +302,7 @@ mmutranslatereal_normal(uint32_t addr, int rw)
 
     if ((temp & 0x80) && (cr4 & CR4_PSE)) {
         /*4MB page*/
-        if (((CPL == 3) && !(temp & 4) && !cpl_override) || (rw && !(temp & 2) && (((CPL == 3) && !cpl_override) || (is486 && (cr0 & WP_FLAG))))) {
+        if (((CPL == 3) && !(temp & 4) && !cpl_override) || (rw && !(temp & 2) && (((CPL == 3) && !cpl_override) || ((is486 || isibm486) && (cr0 & WP_FLAG))))) {
             cr2 = addr;
             temp &= 1;
             if (CPL == 3)
@@ -323,7 +323,7 @@ mmutranslatereal_normal(uint32_t addr, int rw)
 
     temp  = rammap((temp & ~0xfff) + ((addr >> 10) & 0xffc));
     temp3 = temp & temp2;
-    if (!(temp & 1) || ((CPL == 3) && !(temp3 & 4) && !cpl_override) || (rw && !(temp3 & 2) && (((CPL == 3) && !cpl_override) || (is486 && (cr0 & WP_FLAG))))) {
+    if (!(temp & 1) || ((CPL == 3) && !(temp3 & 4) && !cpl_override) || (rw && !(temp3 & 2) && (((CPL == 3) && !cpl_override) || ((is486 || isibm486) && (cr0 & WP_FLAG))))) {
         cr2 = addr;
         temp &= 1;
         if (CPL == 3)
diff --git a/src/qt/qt_hardwarerenderer.cpp b/src/qt/qt_hardwarerenderer.cpp
index 29b3613ea..006eb1d77 100644
--- a/src/qt/qt_hardwarerenderer.cpp
+++ b/src/qt/qt_hardwarerenderer.cpp
@@ -46,7 +46,9 @@ void HardwareRenderer::initializeGL()
 {
     m_context->makeCurrent(this);
     initializeOpenGLFunctions();
-    m_texture = new QOpenGLTexture(QImage(2048,2048, QImage::Format::Format_RGB32));
+    auto image = QImage(2048, 2048, QImage::Format_RGB32);
+    image.fill(0xff000000);
+    m_texture = new QOpenGLTexture(image);
     m_blt = new QOpenGLTextureBlitter;
     m_blt->setRedBlueSwizzle(true);
     m_blt->create();
@@ -138,6 +140,7 @@ void HardwareRenderer::initializeGL()
     pclog("OpenGL shader language version: %s\n", glGetString(GL_SHADING_LANGUAGE_VERSION));
     glClearColor(0, 0, 0, 1);
     m_texture->setWrapMode(QOpenGLTexture::ClampToEdge);
+    update();
 }
 
 void HardwareRenderer::paintGL() {
diff --git a/src/qt/qt_mainwindow.cpp b/src/qt/qt_mainwindow.cpp
index e43db23e7..b164864e8 100644
--- a/src/qt/qt_mainwindow.cpp
+++ b/src/qt/qt_mainwindow.cpp
@@ -154,7 +154,7 @@ MainWindow::MainWindow(QWidget *parent) :
     ui->stackedWidget->setMouseTracking(true);
     statusBar()->setVisible(!hide_status_bar);
     statusBar()->setStyleSheet("QStatusBar::item {border: None; } QStatusBar QLabel { margin-right: 2px; margin-bottom: 1px; }");
-    this->setStyleSheet("#centralWidget { background-color: black; }");
+    this->centralWidget()->setStyleSheet("background-color: black;");
     ui->toolBar->setVisible(!hide_tool_bar);
     renderers[0].reset(nullptr);
     auto toolbar_spacer = new QWidget();
@@ -507,15 +507,6 @@ MainWindow::MainWindow(QWidget *parent) :
 #endif
     if (!vnc_enabled) video_setblit(qt_blit);
 
-    if (start_in_fullscreen) {
-        connect(ui->stackedWidget, &RendererStack::blit, this, [this] () {
-            if (start_in_fullscreen) {
-                QTimer::singleShot(100, ui->actionFullscreen, &QAction::trigger);
-                start_in_fullscreen = 0;
-            }
-        });
-    }
-
 #ifdef MTR_ENABLED
     {
         ui->actionBegin_trace->setVisible(true);
@@ -711,6 +702,10 @@ void MainWindow::showEvent(QShowEvent *event) {
         QApplication::processEvents();
         this->adjustSize();
     }
+    if (start_in_fullscreen) {
+        start_in_fullscreen = 0;
+        QTimer::singleShot(0, ui->actionFullscreen, &QAction::trigger);
+    }
 }
 
 void MainWindow::on_actionKeyboard_requires_capture_triggered() {
diff --git a/src/qt/qt_openglrenderer.cpp b/src/qt/qt_openglrenderer.cpp
index b3e771fea..c7cc3b4e2 100644
--- a/src/qt/qt_openglrenderer.cpp
+++ b/src/qt/qt_openglrenderer.cpp
@@ -14,6 +14,7 @@
  *      Copyright 2022 Teemu Korhonen
  */
 
+#include <GL/gl.h>
 #include <QCoreApplication>
 #include <QMessageBox>
 #include <QOpenGLShaderProgram>
@@ -194,6 +195,9 @@ OpenGLRenderer::initialize()
 
         emit initialized();
 
+        glClear(GL_COLOR_BUFFER_BIT);
+
+        context->swapBuffers(this);
     } catch (const opengl_init_error &e) {
         /* Mark all buffers as in use */
         for (auto &flag : buf_usage)
diff --git a/src/qt/qt_rendererstack.cpp b/src/qt/qt_rendererstack.cpp
index 670a0d0da..2d32f24a8 100644
--- a/src/qt/qt_rendererstack.cpp
+++ b/src/qt/qt_rendererstack.cpp
@@ -416,6 +416,7 @@ RendererStack::createRenderer(Renderer renderer)
     current->setFocusPolicy(Qt::NoFocus);
     current->setFocusProxy(this);
     current->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+    current->setStyleSheet("background-color: black");
     addWidget(current.get());
 
     this->setStyleSheet("background-color: black");