diff --git a/src/libCom/ellLib.c b/src/libCom/ellLib.c
index c95fc692d..91a5c8304 100644
--- a/src/libCom/ellLib.c
+++ b/src/libCom/ellLib.c
@@ -28,16 +28,21 @@
  * -----------------
  * .01	jrw	07-02-92	created
  * .02	rcz	08-26-92	moved to libCom
+ * .03  joh 12-12-97	added ellverify()
  */
 
 /* #define	DEBUG_DRIVER */
 
+
+
 #ifdef vxWorks
 #include <vxWorks.h>
 #endif
 
 #include <stdlib.h>
 
+#include <epicsAssert.h>
+
 #define epicsExportSharedSymbols
 #include "ellLib.h"
 
@@ -487,6 +492,43 @@ ELLLIST *pList;
 
   return;
 }
+
+/****************************************************************************
+ *
+ * This function verifies that the list is consistent.
+ * joh 12-12-97
+ *
+ *****************************************************************************/
+void epicsShareAPI ellVerify (ELLLIST *pList) 
+{
+	ELLNODE *pNode;
+	ELLNODE *pNext;
+	int count;
+
+	assert (pList);
+
+	count = 0u;	
+	pNode = ellFirst(pList);
+	if (pNode) {
+		assert (ellPrevious(pNode)==NULL);
+		while (1) {
+			count++;
+			pNext = ellNext(pNode);
+			if (pNext) {
+				assert (ellPrevious(pNext)==pNode);
+			}
+			else {
+				break;
+			}
+			pNode = pNext;
+		}
+		assert (ellNext(pNode)==NULL);
+	}
+
+	assert (pNode==ellLast(pList));
+	assert (count==ellCount(pList));
+}
+
 #ifdef DEBUG_DRIVER
 /****************************************************************************
  *
diff --git a/src/libCom/ellLib.h b/src/libCom/ellLib.h
index 519151872..8db17270d 100644
--- a/src/libCom/ellLib.h
+++ b/src/libCom/ellLib.h
@@ -29,6 +29,7 @@
  * .01  jrw     07-02-92        created
  * .02  rcz     07-23-93        changed name
  * .03  rcz     07-26-93        changed name again
+ * .04  joh		12-12-97		added ellverify()
  */
 #ifndef INCellLibh
 #define INCellLibh
@@ -92,6 +93,7 @@ epicsShareFunc ELLNODE * epicsShareAPI ellNth (ELLLIST *pList, int nodeNum);
 epicsShareFunc ELLNODE * epicsShareAPI ellNStep (ELLNODE *pNode, int nStep);
 epicsShareFunc int  epicsShareAPI ellFind (ELLLIST *pList, ELLNODE *pNode);
 epicsShareFunc void epicsShareAPI ellFree (ELLLIST *pList);
+epicsShareFunc void epicsShareAPI ellVerify (ELLLIST *pList);
 
 #else				/*__STDC__*/
 
@@ -132,6 +134,8 @@ epicsShareFunc ELLNODE * epicsShareAPI ellNth ();
 epicsShareFunc ELLNODE * epicsShareAPI ellNStep ();
 epicsShareFunc int epicsShareAPI ellFind ();
 epicsShareFunc void epicsShareAPI ellFree ();
+epicsShareFunc void ellVerify ();
+
 #endif				/*__STDC__*/
 
 #ifdef __cplusplus
diff --git a/src/libCom/ellLib/ellLib.c b/src/libCom/ellLib/ellLib.c
index c95fc692d..91a5c8304 100644
--- a/src/libCom/ellLib/ellLib.c
+++ b/src/libCom/ellLib/ellLib.c
@@ -28,16 +28,21 @@
  * -----------------
  * .01	jrw	07-02-92	created
  * .02	rcz	08-26-92	moved to libCom
+ * .03  joh 12-12-97	added ellverify()
  */
 
 /* #define	DEBUG_DRIVER */
 
+
+
 #ifdef vxWorks
 #include <vxWorks.h>
 #endif
 
 #include <stdlib.h>
 
+#include <epicsAssert.h>
+
 #define epicsExportSharedSymbols
 #include "ellLib.h"
 
@@ -487,6 +492,43 @@ ELLLIST *pList;
 
   return;
 }
+
+/****************************************************************************
+ *
+ * This function verifies that the list is consistent.
+ * joh 12-12-97
+ *
+ *****************************************************************************/
+void epicsShareAPI ellVerify (ELLLIST *pList) 
+{
+	ELLNODE *pNode;
+	ELLNODE *pNext;
+	int count;
+
+	assert (pList);
+
+	count = 0u;	
+	pNode = ellFirst(pList);
+	if (pNode) {
+		assert (ellPrevious(pNode)==NULL);
+		while (1) {
+			count++;
+			pNext = ellNext(pNode);
+			if (pNext) {
+				assert (ellPrevious(pNext)==pNode);
+			}
+			else {
+				break;
+			}
+			pNode = pNext;
+		}
+		assert (ellNext(pNode)==NULL);
+	}
+
+	assert (pNode==ellLast(pList));
+	assert (count==ellCount(pList));
+}
+
 #ifdef DEBUG_DRIVER
 /****************************************************************************
  *
diff --git a/src/libCom/ellLib/ellLib.h b/src/libCom/ellLib/ellLib.h
index 519151872..8db17270d 100644
--- a/src/libCom/ellLib/ellLib.h
+++ b/src/libCom/ellLib/ellLib.h
@@ -29,6 +29,7 @@
  * .01  jrw     07-02-92        created
  * .02  rcz     07-23-93        changed name
  * .03  rcz     07-26-93        changed name again
+ * .04  joh		12-12-97		added ellverify()
  */
 #ifndef INCellLibh
 #define INCellLibh
@@ -92,6 +93,7 @@ epicsShareFunc ELLNODE * epicsShareAPI ellNth (ELLLIST *pList, int nodeNum);
 epicsShareFunc ELLNODE * epicsShareAPI ellNStep (ELLNODE *pNode, int nStep);
 epicsShareFunc int  epicsShareAPI ellFind (ELLLIST *pList, ELLNODE *pNode);
 epicsShareFunc void epicsShareAPI ellFree (ELLLIST *pList);
+epicsShareFunc void epicsShareAPI ellVerify (ELLLIST *pList);
 
 #else				/*__STDC__*/
 
@@ -132,6 +134,8 @@ epicsShareFunc ELLNODE * epicsShareAPI ellNth ();
 epicsShareFunc ELLNODE * epicsShareAPI ellNStep ();
 epicsShareFunc int epicsShareAPI ellFind ();
 epicsShareFunc void epicsShareAPI ellFree ();
+epicsShareFunc void ellVerify ();
+
 #endif				/*__STDC__*/
 
 #ifdef __cplusplus