diff --git a/src/as/asCa.c b/src/as/asCa.c
index c205d34d5..9ac266521 100644
--- a/src/as/asCa.c
+++ b/src/as/asCa.c
@@ -175,7 +175,7 @@ LOCAL void asCaTask(void)
     int		status;
 
     taskwdInsert(epicsThreadGetIdSelf(),NULL,NULL);
-    SEVCHK(ca_context_create(enablePreemption,1024),
+    SEVCHK(ca_context_create(enablePreemption),
         "asCaTask calling ca_context_create");
     SEVCHK(ca_add_exception_event(exceptionCallback,NULL),
         "ca_add_exception_event");
diff --git a/src/ca/access.cpp b/src/ca/access.cpp
index 90a0cdd16..50c9d0290 100644
--- a/src/ca/access.cpp
+++ b/src/ca/access.cpp
@@ -88,11 +88,10 @@ int fetchClientContext ( oldCAC **ppcac )
  */
 extern "C" int epicsShareAPI ca_task_initialize ( void )
 {
-    return ca_context_create ( false, 32768 );
+    return ca_context_create ( false );
 }
 
-extern "C" int epicsShareAPI ca_context_create ( 
-                  int preemptiveCallBackEnable, unsigned maxNumberOfChannels )
+extern "C" int epicsShareAPI ca_context_create ( int preemptiveCallBackEnable )
 {
     oldCAC *pcac;
 
@@ -102,12 +101,12 @@ extern "C" int epicsShareAPI ca_context_create (
         return ECA_ALLOCMEM;
     }
 
-    pcac = (oldCAC *) epicsThreadPrivateGet ( caClientContextId );
+    pcac = ( oldCAC * ) epicsThreadPrivateGet ( caClientContextId );
 	if ( pcac ) {
 		return ECA_NORMAL;
 	}
 
-    pcac = new oldCAC ( preemptiveCallBackEnable ? true : false, maxNumberOfChannels );
+    pcac = new oldCAC ( preemptiveCallBackEnable ? true : false );
 	if ( ! pcac ) {
 		return ECA_ALLOCMEM;
 	}
diff --git a/src/db/dbCa.c b/src/db/dbCa.c
index 23671b4ac..d5877dad0 100644
--- a/src/db/dbCa.c
+++ b/src/db/dbCa.c
@@ -648,7 +648,7 @@ void dbCaTask()
     int        status;
 
     taskwdInsert(epicsThreadGetIdSelf(),NULL,NULL);
-    SEVCHK(ca_context_create(enablePreemption,32768),
+    SEVCHK(ca_context_create(enablePreemption),
         "dbCaTask calling ca_context_create");
     SEVCHK(ca_add_exception_event(exceptionCallback,NULL),
         "ca_add_exception_event");
diff --git a/src/db/dbServiceIO.cpp b/src/db/dbServiceIO.cpp
index 2bfd3850e..00daf64d9 100644
--- a/src/db/dbServiceIO.cpp
+++ b/src/db/dbServiceIO.cpp
@@ -52,7 +52,7 @@ dbServiceIOLoadTimeInit::dbServiceIOLoadTimeInit ()
 }
 
 dbServiceIO::dbServiceIO () :
-    ioTable ( 1024 ), eventCallbackCacheSize ( 0ul ),
+    eventCallbackCacheSize ( 0ul ),
         ctx ( 0 ), pEventCallbackCache ( 0 ) 
 {
 }
diff --git a/src/libCom/fdmgr/fdManager.cpp b/src/libCom/fdmgr/fdManager.cpp
index 0e3477800..2ddfaef25 100644
--- a/src/libCom/fdmgr/fdManager.cpp
+++ b/src/libCom/fdmgr/fdManager.cpp
@@ -80,18 +80,17 @@ epicsShareDef fdManager fileDescriptorManager;
 //
 inline const unsigned fdRegId::minIndexBitWidth () 
 {
-    return hashTableIndexBits;
+    return fdManagerHashTableMinIndexBits;
 }
 inline const unsigned fdRegId::maxIndexBitWidth () 
 {
-    return sizeof(SOCKET)*CHAR_BIT;
+    return fdManagerHashTableMaxIndexBits;
 }
 
 //
 // fdManager::fdManager()
 //
-epicsShareFunc fdManager::fdManager () :
-    fdTbl ( 1<<hashTableIndexBits ), pTimerQueue ( 0 )
+epicsShareFunc fdManager::fdManager () : pTimerQueue ( 0 )
 {
     size_t i;
     int status;
diff --git a/src/libCom/fdmgr/fdManager.h b/src/libCom/fdmgr/fdManager.h
index ee21a6603..a4748db59 100644
--- a/src/libCom/fdmgr/fdManager.h
+++ b/src/libCom/fdmgr/fdManager.h
@@ -43,8 +43,6 @@
 #include "osiSock.h"
 #include "epicsTimer.h"
 
-static const unsigned hashTableIndexBits = 8;
-
 enum fdRegType {fdrRead, fdrWrite, fdrException, fdrNEnums};
 
 //
@@ -74,7 +72,7 @@ public:
         return this->fd == idIn.fd && this->type==idIn.type;
     }
 
-    resTableIndex hash (unsigned nBitsId) const;
+    resTableIndex hash () const;
 
     static const unsigned minIndexBitWidth ();
     static const unsigned maxIndexBitWidth ();
@@ -175,15 +173,18 @@ private:
     fdManager &manager;
 };
 
+static const unsigned fdManagerHashTableMinIndexBits = 8;
+static const unsigned fdManagerHashTableMaxIndexBits = sizeof(SOCKET)*CHAR_BIT;
+
 //
 // fdRegId::hash()
 //
-inline resTableIndex fdRegId::hash (unsigned) const
+inline resTableIndex fdRegId::hash () const
 {
     resTableIndex hashid;
         
-    hashid = intId<SOCKET, hashTableIndexBits, sizeof(SOCKET)*CHAR_BIT>
-        ::hashEngine(this->fd);
+    hashid = integerHash < fdManagerHashTableMinIndexBits, 
+        fdManagerHashTableMaxIndexBits > ( this->fd );
  
     //
     // also evenly distribute based on the type of fdRegType
diff --git a/src/libCom/fdmgr/fdmgr.cpp b/src/libCom/fdmgr/fdmgr.cpp
index 26c5b6fca..9954b7299 100644
--- a/src/libCom/fdmgr/fdmgr.cpp
+++ b/src/libCom/fdmgr/fdmgr.cpp
@@ -149,9 +149,7 @@ epicsTimerNotify::expireStatus timerForOldFdmgr::expire ( const epicsTime & )
     return noRestart;
 }
 
-oldFdmgr::oldFdmgr () : resTbl (1024)
-{
-}
+oldFdmgr::oldFdmgr () {}
 
 extern "C" epicsShareFunc fdctx * epicsShareAPI fdmgr_init (void)
 {