diff --git a/myhdl/simrunc.c b/myhdl/simrunc.c
new file mode 100644
index 00000000..51017b30
--- /dev/null
+++ b/myhdl/simrunc.c
@@ -0,0 +1,205 @@
+#include "Python.h"
+
+#include <assert.h>
+
+static PyObject *_simulator;
+static PyObject *_siglist;
+static PyObject *_futureEvents;
+static PyObject *_WaiterList;
+static PyObject *_Waiter;
+static PyObject *Signal;
+static PyObject *delay;
+static PyObject *StopSimulation;
+static PyObject *SuspendSimulation;
+
+
+PyObject *
+run(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+
+    PyObject *sim;
+    long int duration = 0;
+    int quiet = 0;
+    static char *argnames[] = {"sim", "duration", "quiet", NULL};
+
+    PyObject *waiters, *waiter, *clauses, *clone, *clause, *type, *newtO, *event;
+    long long int maxTime = -1;
+    long long int t = 0;
+    long long int ct = 0;
+    long long int newt = 0;
+    int nr;
+    int len, i, j;
+    PyObject *tO, *extl, *s, *hr, *hgl, *nt, *c, *wl, *ev, *ctO, *r;
+
+
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs, "O|li", argnames, 
+				     &sim, &duration, &quiet)) {
+	return NULL;
+    }
+    waiters = PyObject_GetAttrString(sim, "_waiters");
+    tO = PyObject_GetAttrString(_simulator, "_time");
+    t = PyLong_AsLongLong(tO);
+    Py_DECREF(tO);
+
+
+    for (;;) {
+
+
+	len = PyList_Size(_siglist);
+	for (i = 0; i < len; i++) {
+	    s = PyList_GetItem(_siglist, i);
+	    extl = PyObject_CallMethod(s, "_update", NULL);
+	    for (j = 0; j < PyList_Size(extl); j++) {
+		PyList_Append(waiters, PyList_GetItem(extl, j));
+	    }
+	    Py_DECREF(extl);
+	}
+	PySequence_DelSlice(_siglist, 0, len);
+
+	while (PyList_Size(waiters) > 0) {
+	    waiter = PyList_GetItem(waiters, 0);
+	    Py_INCREF(waiter);
+	    PySequence_DelItem(waiters, 0);
+	    hr = PyObject_GetAttrString(waiter, "hasRun");
+	    if (PyObject_IsTrue(hr)) {
+		Py_DECREF(waiter);
+		Py_DECREF(hr);
+		continue;
+	    }
+	    Py_DECREF(hr);
+	    hgl = PyObject_CallMethod(waiter, "hasGreenLight", NULL);
+	    if (!PyObject_IsTrue(hgl)) {
+		Py_DECREF(waiter);
+		Py_DECREF(hgl);
+		continue;
+	    }
+	    Py_DECREF(hgl);
+	    nt = PyObject_CallMethod(waiter, "next", NULL);
+	    if (nt == NULL) {
+		if (PyErr_ExceptionMatches(PyExc_StopIteration)) {
+		    c = PyObject_GetAttrString(waiter, "caller");
+		    if (c != Py_None) {
+			PyList_Append(waiters, c);
+		    }
+		    Py_DECREF(waiter);
+		    Py_DECREF(c);
+		    continue;
+		} else {
+		    goto exception;
+		}
+	    }
+	    clauses = PyTuple_GetItem(nt, 0);
+	    clone = PyTuple_GetItem(nt, 1);
+	    nr = PyTuple_Size(clauses);
+	    for (i = 0; i < nr; i++) {
+		clause = PySequence_GetItem(clauses, i);
+		type = PyObject_Type(clause);
+		if (type == _WaiterList) {
+		    PyList_Append(clause, clone);
+		} else if (PyObject_IsInstance(clause, Signal)) {
+		    wl = PyObject_GetAttrString(clause, "_eventWaiters");
+		    PyList_Append(wl, clone);
+		    Py_DECREF(wl);
+		} else if (type == delay) {
+		    ctO = PyObject_GetAttrString(clause, "_time");
+		    ct = PyLong_AsLongLong(ctO);
+		    Py_DECREF(ctO);
+		    ev = PyTuple_New(2);
+		    newtO = PyLong_FromLongLong(t + ct);
+		    PyTuple_SetItem(ev, 0, newtO);
+		    PyTuple_SetItem(ev, 1, clone);
+		    PyList_Append(_futureEvents, ev);
+		    Py_DECREF(ev);
+		} else {
+		    assert(0);
+		}
+		Py_DECREF(clause);
+	    }
+	    Py_DECREF(nt);
+	}
+
+
+	if (PyList_Size(_siglist) > 0) {
+	    continue;
+	}
+
+	if (PyList_Size(_futureEvents) > 0) {
+	    PyObject_CallMethod(_futureEvents, "sort", NULL);
+	    newtO = PyTuple_GetItem(PyList_GetItem(_futureEvents, 0), 0);
+	    PyObject_SetAttrString(_simulator, "_time", newtO);
+	    t = PyLong_AsLongLong(newtO);
+	    while (PyList_Size(_futureEvents) > 0) {
+		ev = PyList_GetItem(_futureEvents, 0);
+		newtO = PyTuple_GetItem(ev, 0);
+		newt = PyLong_AsLongLong(newtO);
+		event = PyTuple_GetItem(ev, 1);
+		if (newt == t) {
+		    if (PyObject_Type(event) == _Waiter) {
+			PyList_Append(waiters, event);
+		    } else {
+			extl = PyObject_CallMethod(event, "apply", NULL);
+			for (j = 0; j < PyList_Size(extl); j++) {
+			    PyList_Append(waiters, PyList_GetItem(extl, j));
+			}
+			Py_DECREF(extl);
+		    }
+		    PySequence_DelItem(_futureEvents, 0);
+		} else {
+		    break;
+		}
+	    }
+
+	} else {
+	    PyErr_SetString(StopSimulation, "No more events");
+	    printf("No more events\n");
+	    goto exception;
+	}
+    }
+
+    assert(0); /* should not get here */
+
+ exception:
+    if (PyErr_ExceptionMatches(StopSimulation)) {
+	printf("Stop simulation reached \n");
+	PyErr_Clear();
+	r = PyObject_CallMethod(sim, "_finalize", NULL);
+	Py_DECREF(r);
+	return PyInt_FromLong(0);
+    }
+    return Py_BuildValue("");
+}
+
+
+static PyMethodDef simruncmethods[] = {
+    {"run", (PyCFunction)run, METH_VARARGS | METH_KEYWORDS},
+    {NULL, NULL, 0, NULL}
+};
+
+void initsimrunc(void) {
+    PyObject *SignalModule;
+    PyObject *delayModule;
+    PyObject *_WaiterModule;
+    PyObject *utilModule;
+
+    Py_InitModule("simrunc", simruncmethods);
+
+    _simulator = PyImport_ImportModule("_simulator");
+    _siglist = PyObject_GetAttrString(_simulator, "_siglist");
+    _futureEvents = PyObject_GetAttrString(_simulator, "_futureEvents");
+    SignalModule = PyImport_ImportModule("Signal");
+    Signal = PyObject_GetAttrString(SignalModule, "Signal");
+    _WaiterList = PyObject_GetAttrString(SignalModule, "_WaiterList");
+    delayModule = PyImport_ImportModule("delay");
+    delay = PyObject_GetAttrString(delayModule, "delay");
+    _WaiterModule = PyImport_ImportModule("_Waiter");
+    _Waiter = PyObject_GetAttrString(_WaiterModule, "_Waiter");
+    utilModule = PyImport_ImportModule("util");
+    StopSimulation = PyObject_GetAttrString(utilModule, "StopSimulation");
+    SuspendSimulation = PyObject_GetAttrString(utilModule, "SuspendSimulation");
+
+    Py_DECREF(SignalModule);
+    Py_DECREF(delayModule);
+    Py_DECREF(_WaiterModule);
+    Py_DECREF(utilModule);
+}