diff --git a/sources/PPU/Background.cpp b/sources/PPU/Background.cpp
index 7015c0e..f21406c 100644
--- a/sources/PPU/Background.cpp
+++ b/sources/PPU/Background.cpp
@@ -56,6 +56,7 @@ namespace ComSquare::PPU
 
 		tileData.raw = data;
 		palette = getPalette(tileData.palette);
+		// TODO explain X and Y and rethink the formula
 		graphicAddress = this->_tileSetAddress + (tileData.posX * 16 * this->_bpp * 8) + (tileData.posY * this->_bpp * 8);
 		for (int i = 0; i < this->_characterSize.y; i++) {
 			for (int j = 0; j < this->_characterSize.x; j++) {
@@ -127,7 +128,7 @@ namespace ComSquare::PPU
 		Vector2<int> pos(0,0);
 		uint16_t vramAddress = baseAddress;
 
-		while (vramAddress < 0x800 + baseAddress) {
+		while (vramAddress < baseAddress + 0x800) {
 			tileMapValue = this->_vram->read_internal(vramAddress);
 			tileMapValue += this->_vram->read_internal(vramAddress + 1) << 8U;
 			drawBgTile(tileMapValue, {(pos.x * this->_characterSize.x) + offset.x, (pos.y * this->_characterSize.y) + offset.y});
diff --git a/sources/PPU/PPU.cpp b/sources/PPU/PPU.cpp
index b0092a8..6ecd720 100644
--- a/sources/PPU/PPU.cpp
+++ b/sources/PPU/PPU.cpp
@@ -595,8 +595,10 @@ namespace ComSquare::PPU
 		for (auto & _background : this->_backgrounds)
 			_background.renderBackground();
 
+		// TODO make a function getDefaultBgColor
 		colorPalette = this->cgram->read_internal(0);
 		colorPalette += this->cgram->read_internal(1) << 8U;
+
 		for (unsigned long i = 0; i < this->_subScreen.size(); i++)
 			for (unsigned long j = 0; j < this->_subScreen[i].size(); j++)
 				this->_subScreen[i][j] = getRealColor(colorPalette);
@@ -679,6 +681,7 @@ namespace ComSquare::PPU
 			//sprites priority 2
 			this->addToMainSubScreen(this->_backgrounds[bgName::bg1Priority]);
 			//sprites priority 3
+            break;
 		case 7:
 			// Not implemented
 		default:
diff --git a/ui/ui_cpu.h b/ui/ui_cpu.h
index f26b484..533450f 100644
--- a/ui/ui_cpu.h
+++ b/ui/ui_cpu.h
@@ -25,7 +25,7 @@
 #include <QtWidgets/QTableView>
 #include <QtWidgets/QToolBar>
 #include <QtWidgets/QWidget>
-//efef
+
 QT_BEGIN_NAMESPACE
 
 class Ui_CPUView