diff --git a/include/Block.hpp b/include/Block.hpp
index ac86ef7..76a038e 100644
--- a/include/Block.hpp
+++ b/include/Block.hpp
@@ -17,11 +17,11 @@ namespace nts {
 
         Block(QGraphicsItem *parent = 0);
 
-        Port *addPort(const QString &name, const Pin* pin, bool isOutput, int flags = 0, int ptr = 0);
+        Port *addPort(const QString &name, Pin* pin, bool isOutput, int flags = 0, int ptr = 0);
 
-        void addInputPort(const QString &name, const Pin *pin);
+        void addInputPort(const QString &name, Pin *pin);
 
-        void addOutputPort(const QString &name, const Pin *pin);
+        void addOutputPort(const QString &name, Pin *pin);
 
         void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
 
@@ -29,15 +29,17 @@ namespace nts {
 
         Port *getPortFromPinId(size_t index);
 
+        size_t getPinIdFromPin(Pin *pin);
+
         Block *clone();
 
         QVector<Port *> ports();
 
         int type() const { return Type; }
 
-        const AComponent *getAComponent();
+        AComponent *getAComponent();
 
-        void setAComponent(const AComponent *component);
+        void setAComponent(AComponent *component);
 
     protected:
         QVariant itemChange(GraphicsItemChange change, const QVariant &value);
@@ -47,7 +49,7 @@ namespace nts {
         int vertMargin;
         int width;
         int height;
-        const AComponent *aComponent;
+        AComponent *aComponent;
     };
 }
 #endif // QNEBLOCK_H
diff --git a/include/Connection.hpp b/include/Connection.hpp
index 7b961db..c0e5d26 100644
--- a/include/Connection.hpp
+++ b/include/Connection.hpp
@@ -2,6 +2,7 @@
 #define QNECONNECTION_H
 
 #include <QGraphicsPathItem>
+#include <qpainter.h>
 
 
 namespace nts {
@@ -25,6 +26,10 @@ namespace nts {
 
         void setPort2(Port *p);
 
+        Port *getPort1();
+
+        Port *getPort2();
+
         void updatePosFromPorts();
 
         void updatePath();
@@ -35,6 +40,7 @@ namespace nts {
 
         int type() const { return Type; }
 
+        void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget);
     private:
         ::QPointF pos1;
         ::QPointF pos2;
diff --git a/include/MainWindow.hpp b/include/MainWindow.hpp
index 5d153bf..6edf7c4 100644
--- a/include/MainWindow.hpp
+++ b/include/MainWindow.hpp
@@ -3,6 +3,7 @@
 
 #include <QMainWindow>
 #include <QtWidgets>
+#include <qmenubar.h>
 #include "AComponent.hpp"
 #include "IComponent.hpp"
 #include "Pin.hpp"
@@ -30,6 +31,8 @@ namespace nts {
 
         void loadFile();
 
+        void simulate();
+
         void addComponent(std::string name);
 
     private:
@@ -37,7 +40,7 @@ namespace nts {
         QMenu *fileMenu;
         EditorView *view;
         QGraphicsScene *scene;
-        std::list<Block*> *blocks;
+        std::vector<Block*> *blocks;
 
         std::vector<Pin> getPorts(AComponent *component);
     };
diff --git a/include/Port.hpp b/include/Port.hpp
index 86c40ed..37bb41d 100644
--- a/include/Port.hpp
+++ b/include/Port.hpp
@@ -43,7 +43,7 @@ namespace nts {
 
         int type() const { return Type; }
 
-        Block *block() const;
+        Block *block();
 
         quint64 ptr();
 
@@ -51,9 +51,9 @@ namespace nts {
 
         bool isConnected(Port *);
 
-        void setPin(const Pin* pin);
+        void setPin(Pin* pin);
 
-        const Pin *getPin();
+        Pin *getPin();
     protected:
         QVariant itemChange(GraphicsItemChange change, const QVariant &value);
 
@@ -67,7 +67,7 @@ namespace nts {
         QVector<Connection *> m_connections;
         int m_portFlags;
         quint64 m_ptr;
-        const Pin *pin;
+        Pin *pin;
     };
 }
 #endif // QNEPORT_H
diff --git a/src/components/Pin.cpp b/src/components/Pin.cpp
index 396bf47..eef86c3 100644
--- a/src/components/Pin.cpp
+++ b/src/components/Pin.cpp
@@ -1,42 +1,45 @@
 #include "Pin.hpp"
 
-namespace nts
-{
-    Pin::Pin(Mode _mode) : mode(_mode), component(0), state(UNDEFINED), target_pin(0)
-    {
+namespace nts {
+    Pin::Pin(Mode _mode) : mode(_mode), component(0), state(UNDEFINED), target_pin(0) {
     }
 
-    Pin::Pin(const Pin &other) : mode(other.getMode()), component(&other.getComponent()), state(other.getState()), target_pin(other.getTargetPin())
-    {
+    Pin::Pin(const Pin &other) : mode(other.getMode()), component(&other.getComponent()), state(other.getState()),
+                                 target_pin(other.getTargetPin()) {
     }
 
-    Pin::~Pin()
-    {
+    Pin::~Pin() {
     }
 
-    const Pin &Pin::operator=(const Pin &other)
-    {
+    const Pin &Pin::operator=(const Pin &other) {
         this->component = &other.getComponent();
         this->state = other.getState();
         this->target_pin = other.getTargetPin();
         return (*this);
     }
 
-    void Pin::setComponent(IComponent &_component) {this->component = &_component;}
+    void Pin::setComponent(IComponent &_component) {
+        printf("setComponent %p\n", &_component);
+        this->component = &_component;
+    }
 
-    void Pin::setTarget(std::size_t _target_pin) {this->target_pin = _target_pin;}
+    void Pin::setTarget(std::size_t _target_pin) { this->target_pin = _target_pin; }
 
-    void Pin::setState(Tristate _state) {this->state = _state;}
+    void Pin::setState(Tristate _state) { this->state = _state; }
 
-    void Pin::setMode(Mode _mode) {this->mode = _mode;}
+    void Pin::setMode(Mode _mode) { this->mode = _mode; }
 
-    IComponent &Pin::getComponent() const {return (*this->component);}
+    IComponent &Pin::getComponent() const { return (*this->component); }
 
-    std::size_t Pin::getTargetPin() const {return (this->target_pin);}
+    std::size_t Pin::getTargetPin() const { return (this->target_pin); }
 
-    Tristate Pin::getState() const {return (this->state);}
+    Tristate Pin::getState() const { return (this->state); }
 
-    nts::Tristate Pin::compute() {return (this->component->Compute(this->target_pin));}
+    nts::Tristate Pin::compute() {
+        if (this->component == NULL)
+            return nts::Tristate::UNDEFINED;
+        return (this->component->Compute(this->target_pin));
+    }
 
-    Pin::Mode Pin::getMode() const {return (this->mode);}
+    Pin::Mode Pin::getMode() const { return (this->mode); }
 }
diff --git a/src/editor/Editor.cpp b/src/editor/Editor.cpp
index a7817d0..b47bf06 100644
--- a/src/editor/Editor.cpp
+++ b/src/editor/Editor.cpp
@@ -81,6 +81,17 @@ namespace nts {
                             !port1->isConnected(port2)) {
                             conn->setPos2(port2->scenePos());
                             conn->setPort2(port2);
+
+                            if (conn->getPort1()->getPin()->getMode() == Pin::Mode::O && conn->getPort2()->getPin()->getMode() == Pin::Mode::I) {
+                                conn->getPort2()->getPin()->setComponent(*conn->getPort1()->block()->getAComponent());
+                                conn->getPort2()->getPin()->setTarget(conn->getPort1()->block()->getPinIdFromPin(conn->getPort1()->getPin()));
+                                conn->getPort2()->getPin()->setState(conn->getPort2()->getPin()->compute());
+                            } else if (conn->getPort1()->getPin()->getMode() == Pin::Mode::I && conn->getPort2()->getPin()->getMode() == Pin::Mode::O) {
+                                conn->getPort1()->getPin()->setComponent(*conn->getPort2()->block()->getAComponent());
+                                conn->getPort1()->getPin()->setTarget(conn->getPort2()->block()->getPinIdFromPin(conn->getPort2()->getPin()));
+                                conn->getPort1()->getPin()->setState(conn->getPort1()->getPin()->compute());
+                            }
+// TODO need to support all
                             conn->updatePath();
                             conn = 0;
                             return true;
diff --git a/src/editor/MainWindow.cpp b/src/editor/MainWindow.cpp
index 1f179fa..ae1a679 100644
--- a/src/editor/MainWindow.cpp
+++ b/src/editor/MainWindow.cpp
@@ -41,12 +41,18 @@ namespace nts {
         saveAct->setStatusTip(tr("Save a file"));
         connect(saveAct, SIGNAL(triggered()), this, SLOT(saveFile()));
 
+        QAction *simulateAct = new QAction(tr("&Simulate"), this);
+        saveAct->setStatusTip(tr("Simulate"));
+        connect(simulateAct, SIGNAL(triggered()), this, SLOT(simulate()));
+
         fileMenu = menuBar()->addMenu(tr("&File"));
         fileMenu->addAction(loadAct);
         fileMenu->addAction(saveAct);
         fileMenu->addSeparator();
         fileMenu->addAction(quitAct);
 
+        menuBar()->addAction(simulateAct);
+
         setWindowTitle(tr("Nanotekspice"));
 
         view = new EditorView();
@@ -61,7 +67,7 @@ namespace nts {
         nodesEditor = new Editor(this);
         nodesEditor->install(scene);
 
-        blocks = new std::list<Block *>();
+        blocks = new std::vector<Block *>();
 
         this->setMinimumWidth(480);
         this->setMinimumHeight(640);
@@ -108,7 +114,7 @@ namespace nts {
 
         Block *b = new Block(0);
         scene->addItem(b);
-        blocks->push_front(b);
+        blocks->push_back(b);
         b->setAComponent(component);
         b->addPort(QString::fromStdString(component->getName()), NULL, 0, Port::NamePort);
 
@@ -116,30 +122,30 @@ namespace nts {
 
         b->setPos(pos.x(), pos.y() - 10);
 
-        for (const auto &pin : component->getPins()) {
+        for (auto &pin : component->getPins()) {
             switch (pin.getMode()) {
                 case Pin::Mode::U:
-                    b->addInputPort("UNDEFINED", &pin);
+                    b->addInputPort("UNDEFINED", const_cast<Pin*>(&pin));
                     break;
 
                 case Pin::Mode::I:
-                    b->addInputPort("IN " + pin.getTargetPin(), &pin);
+                    b->addInputPort("IN " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                     break;
 
                 case Pin::Mode::O:
-                    b->addOutputPort("OUT " + pin.getTargetPin(), &pin);
+                    b->addOutputPort("OUT " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                     break;
 
                 case Pin::Mode::IO:
-                    b->addOutputPort("IN/OUT" + pin.getTargetPin(), &pin);
+                    b->addOutputPort("IN/OUT" + pin.getTargetPin(), const_cast<Pin*>(&pin));
                     break;
 
                 case Pin::Mode::VSS:
-                    b->addOutputPort("VSS " + pin.getTargetPin(), &pin);
+                    b->addOutputPort("VSS " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                     break;
 
                 case Pin::Mode::VDD:
-                    b->addOutputPort("VDD " + pin.getTargetPin(), &pin);
+                    b->addOutputPort("VDD " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                     break;
             }
         }
@@ -165,8 +171,16 @@ namespace nts {
         QDataStream ds(&f);
     }
 
+    void MainWindow::simulate() {
+        for (const auto &block : *blocks) {
+            if (const_cast<nts::AComponent *>(block->getAComponent())->getType() == nts::AComponent::Type::IC) {
+                const_cast<nts::AComponent *>(block->getAComponent())->Compute(1);
+            }
+        }
+    }
+
     void MainWindow::setComponents(std::vector<AComponent *> components) {
-        blocks = new std::list<Block *>();
+        blocks = new std::vector<Block *>();
 
         int index = 0;
         for (const auto &component : components) {
@@ -174,7 +188,7 @@ namespace nts {
             Block *b = new Block(0);
             b->setPos(120 * index, index / 3 * 120);
             scene->addItem(b);
-            blocks->push_front(b);
+            blocks->push_back(b);
             b->setAComponent(component);
             b->addPort(QString::fromStdString(component->getName()), NULL, 0, Port::NamePort);
 
@@ -183,27 +197,27 @@ namespace nts {
             for (const auto &pin : component->getPins()) {
                 switch (pin.getMode()) {
                     case Pin::Mode::U:
-                        b->addInputPort("UNDEFINED", &pin);
+                        b->addInputPort("UNDEFINED", const_cast<Pin*>(&pin));
                         break;
 
                     case Pin::Mode::I:
-                        b->addInputPort("IN " + pin.getTargetPin(), &pin);
+                        b->addInputPort("IN " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                         break;
 
                     case Pin::Mode::O:
-                        b->addOutputPort("OUT " + pin.getTargetPin(), &pin);
+                        b->addOutputPort("OUT " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                         break;
 
                     case Pin::Mode::IO:
-                        b->addOutputPort("IN/OUT" + pin.getTargetPin(), &pin);
+                        b->addOutputPort("IN/OUT" + pin.getTargetPin(), const_cast<Pin*>(&pin));
                         break;
 
                     case Pin::Mode::VSS:
-                        b->addOutputPort("VSS " + pin.getTargetPin(), &pin);
+                        b->addOutputPort("VSS " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                         break;
 
                     case Pin::Mode::VDD:
-                        b->addOutputPort("VDD " + pin.getTargetPin(), &pin);
+                        b->addOutputPort("VDD " + pin.getTargetPin(), const_cast<Pin*>(&pin));
                         break;
                 }
             }
diff --git a/src/editor/elements/Block.cpp b/src/editor/elements/Block.cpp
index a18d414..1ff6741 100644
--- a/src/editor/elements/Block.cpp
+++ b/src/editor/elements/Block.cpp
@@ -25,7 +25,7 @@ namespace nts {
         height = vertMargin;
     }
 
-    Port *Block::addPort(const QString &name, const Pin* pin, bool isOutput, int flags, int ptr) {
+    Port *Block::addPort(const QString &name, Pin* pin, bool isOutput, int flags, int ptr) {
         Port *port = new Port(this);
         port->setName(name);
         port->setIsOutput(isOutput);
@@ -62,11 +62,11 @@ namespace nts {
         return port;
     }
 
-    void Block::addInputPort(const QString &name, const Pin *pin) {
+    void Block::addInputPort(const QString &name, Pin *pin) {
         addPort(name, pin, false);
     }
 
-    void Block::addOutputPort(const QString &name, const Pin *pin) {
+    void Block::addOutputPort(const QString &name, Pin *pin) {
         addPort(name, pin, true);
     }
 
@@ -84,6 +84,16 @@ namespace nts {
         return getPortFromPin(&(this->getAComponent()->getPins()[index - 1]));
     }
 
+    size_t Block::getPinIdFromPin(Pin *pin) {
+        size_t pin_id = 0;
+        for (const auto &port : ports()) {
+            if (port->getPin() == pin)
+                return pin_id;
+            pin_id++;
+        }
+        return -1;
+    }
+
     void Block::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
         Q_UNUSED(option)
         Q_UNUSED(widget)
@@ -128,11 +138,11 @@ namespace nts {
         return value;
     }
 
-    void Block::setAComponent(const AComponent *component) {
+    void Block::setAComponent(AComponent *component) {
         this->aComponent = component;
     }
 
-    const AComponent *Block::getAComponent() {
+    AComponent *Block::getAComponent() {
         return this->aComponent;
     }
 }
\ No newline at end of file
diff --git a/src/editor/elements/Connection.cpp b/src/editor/elements/Connection.cpp
index 63009da..3fb8292 100644
--- a/src/editor/elements/Connection.cpp
+++ b/src/editor/elements/Connection.cpp
@@ -2,8 +2,6 @@
 
 #include "Port.hpp"
 
-#include <QBrush>
-#include <QPen>
 #include <QGraphicsScene>
 
 namespace nts {
@@ -42,6 +40,14 @@ namespace nts {
         m_port2->connections().append(this);
     }
 
+    Port *Connection::getPort1() {
+        return this->m_port1;
+    }
+
+    Port *Connection::getPort2() {
+        return this->m_port2;
+    }
+
     void Connection::updatePosFromPorts() {
         pos1 = m_port1->scenePos();
         pos2 = m_port2->scenePos();
@@ -70,4 +76,27 @@ namespace nts {
     Port *Connection::port2() const {
         return m_port2;
     }
+
+    void Connection::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
+        Q_UNUSED(option)
+        Q_UNUSED(widget)
+
+        if ((m_port2 == NULL)) {
+            painter->setPen(QPen(Qt::black, 2));
+            painter->setBrush(Qt::NoBrush);
+
+            painter->drawPath(path());
+            return;
+        }
+
+        if (m_port2->getPin()->getState() == TRUE) {
+            painter->setPen(QPen(Qt::red, 2));
+            painter->setBrush(Qt::NoBrush);
+        } else {
+            painter->setPen(QPen(Qt::black, 2));
+            painter->setBrush(Qt::NoBrush);
+        }
+
+        painter->drawPath(path());
+    }
 }
\ No newline at end of file
diff --git a/src/editor/elements/Port.cpp b/src/editor/elements/Port.cpp
index c075e6d..dceb972 100644
--- a/src/editor/elements/Port.cpp
+++ b/src/editor/elements/Port.cpp
@@ -58,11 +58,11 @@ namespace nts {
         return isOutput_;
     }
 
-    void Port::setPin(const Pin* pin) {
+    void Port::setPin(Pin* pin) {
         this->pin = pin;
     }
 
-    const Pin *Port::getPin() {
+    Pin *Port::getPin() {
         return this->pin;
     }
 
@@ -86,7 +86,7 @@ namespace nts {
         }
     }
 
-    Block *Port::block() const {
+    Block *Port::block() {
         return m_block;
     }