diff --git a/conman.c b/conman.c
index a823014d..13985832 100644
--- a/conman.c
+++ b/conman.c
@@ -2437,4 +2437,43 @@ void SCSetProtocolID(SConnection *pCon, int id)
   }
   pCon->iProtocolID = id;
 }
+/*--------------------------------------------------------*/
+void SCCostaLock(SConnection *pCon)
+{
+  if (!VerifyConnection(pCon)) {
+    return;
+  }
+  CostaLock(pCon->pStack);
+}
+/*---------------------------------------------------------*/
+void SCCostaUnLock(SConnection *pCon){
+  if (!VerifyConnection(pCon)) {
+    return;
+  }
+  CostaUnlock(pCon->pStack);
+}
+/*---------------------------------------------------------*/
+int SCCostaLocked(SConnection *pCon)
+{
+  if (!VerifyConnection(pCon)) {
+    return 0;
+  }
+  return CostaLocked(pCon->pStack);
+}
+/*----------------------------------------------------------*/
+int SCCostaTop(SConnection *pCon, char *command)
+{
+  if (!VerifyConnection(pCon)) {
+    return 0;
+  }
+  return CostaTop(pCon->pStack, command);
+}
+/*----------------------------------------------------------*/
+void SCSetGrab(SConnection *pCon, int iGrab)
+{
+  if (!VerifyConnection(pCon)) {
+    return;
+  }
+  pCon->iGrab = iGrab;
+}
 
diff --git a/conman.h b/conman.h
index 9461a059..4492c426 100644
--- a/conman.h
+++ b/conman.h
@@ -153,6 +153,7 @@ void SCSetConStatus(SConnection *pCon, int conStatus);
 void SCSetEventType(SConnection *pCon, int eventType);
 void SCSetSicsError(SConnection *pCon, int sicsError);
 void SCSetProtocolID(SConnection *pCon, int proID);
+void SCSetGrab(SConnection *pCon, int iGrab);
 
 /* **************************** Invocation ******************************** */
 int SCInvoke(SConnection * self, SicsInterp * pInter, char *pCommand);
@@ -195,4 +196,10 @@ int SCUnregisterID(SConnection * pCon, long ID);
     * returns -1 if no ID can be found.
     */
 long SCgetCallbackID(SConnection * pCon, void *pData);
+/*************************** command stack handling **********************/
+void SCCostaLock(SConnection *pCon);
+void SCCostaUnLock(SConnection *pCon);
+int SCCostaLocked(SConnection *pCon);
+int SCCostaTop(SConnection *pCon, char *command);
+
 #endif
diff --git a/nread.c b/nread.c
index d23ced32..1c9d9a9d 100644
--- a/nread.c
+++ b/nread.c
@@ -1067,10 +1067,10 @@ static int CommandDataCB(int handle, void *userData)
       if (pPtr[i] == '\r' || pPtr[i] == '\n') {
         self->state = SKIPTERM;
         if (!testAndInvokeInterrupt(self, handle)) {
-          if (self->pCon->iProtocolID == PROTSICS && CostaLocked(self->pCon->pStack))
+          if (SCGetProtocolID(self->pCon) == PROTSICS && SCCostaLocked(self->pCon))
             status = 0;
           else
-            status = CostaTop(self->pCon->pStack, GetCharArray(self->command));
+            status = SCCostaTop(self->pCon, GetCharArray(self->command));
           if (!status) {
             SCWrite(self->pCon, "ERROR: Busy", eError);
           }
@@ -1171,10 +1171,10 @@ static int ANETTelnetProcess(int handle, void *usData)
       case '\r':
       case '\n':
         if (!testAndInvokeInterrupt(self, handle)) {
-          if (self->pCon->iProtocolID == PROTSICS && CostaLocked(self->pCon->pStack))
+          if (SCGetProtocolID(self->pCon) == PROTSICS && SCCostaLocked(self->pCon))
             status = 0;
           else
-            status = CostaTop(self->pCon->pStack, GetCharArray(self->command));
+            status = SCCostaTop(self->pCon, GetCharArray(self->command));
           if (!status) {
             SCWrite(self->pCon, "ERROR: Busy", eError);
           }
diff --git a/nserver.c b/nserver.c
index 927be665..d40434f9 100644
--- a/nserver.c
+++ b/nserver.c
@@ -201,17 +201,6 @@ int InitServer(char *file, pServer * pServ)
     IFDeleteOptions(pSICSOptions);
     return 0;
   }
-  /*
-     self->pServerPort = NETOpenPort(iPort);
-     if(!self->pServerPort)
-     {
-     printf("Cannot open Server Socket\n");
-     DeleteInterp(self->pSics);
-     IFDeleteOptions(pSICSOptions);
-     return 0;
-     }
-     NetReadRegister(pReader, self->pServerPort, naccept, NULL);
-   */
   NetReadInstallANETPort(pReader, naccept, iPort);
 
   /* the device executor */
diff --git a/token.c b/token.c
index 2305efb4..942044d0 100644
--- a/token.c
+++ b/token.c
@@ -94,11 +94,11 @@ int TokenWrapper(SConnection * pCon, SicsInterp * pSics, void *pData,
     /* we can do it */
     iToken = 1;
     TaskSignal(pServ->pTasker, TOKENGRAB, NULL);
-    pCon->iGrab = 0;            /* to enable us to do commands */
+    SCSetGrab(pCon,0);            /* to enable us to do commands */
     SCSendOK(pCon);
     return 1;
   } else if (strcmp(argv[1], "release") == 0) {
-    if (pCon->iGrab != 0) {
+    if (SCGetGrab(pCon) != 0) {
       SCWrite(pCon,
               "ERROR: you cannot release somebody elses control token!",
               eError);