diff --git a/cmAudDsp.c b/cmAudDsp.c
index 46ac5e5..69f7f0c 100644
--- a/cmAudDsp.c
+++ b/cmAudDsp.c
@@ -943,12 +943,12 @@ cmAdRC_t _cmAudDspLoadPgm( cmAd_t* p, unsigned asSubSysIdx, unsigned pgmIdx )
 
   // the audio system must be configured before a program is loaded
   if((rc = _cmAdIsAudioSysLoaded(p)) != kOkAdRC )
-    return cmErrMsg(&p->err,rc,"Program load failed.");
+    return cmErrMsg(&p->err,rc,"The audio system is not configured. Program load failed.");
 
   // validate the sub-system index arg.
   if( asSubSysIdx!=cmInvalidIdx && asSubSysIdx >= p->dsSsCnt )
   {
-    rc = cmErrMsg(&p->err,kInvalidSubSysIdxAdRC,"The sub-system index %i is invalid.",asSubSysIdx);
+    rc = cmErrMsg(&p->err,kInvalidSubSysIdxAdRC,"The sub-system index %i is invalid. Program load failed.",asSubSysIdx);
     goto errLabel;
   }
 
@@ -982,6 +982,36 @@ cmAdRC_t _cmAudDspLoadPgm( cmAd_t* p, unsigned asSubSysIdx, unsigned pgmIdx )
   return rc;
 }
 
+cmAdRC_t _cmAudDspPrintPgm( cmAd_t* p, unsigned asSubSysIdx, const cmChar_t* fn )
+{
+  cmAdRC_t rc = kOkAdRC;
+  unsigned i;
+
+  // the audio system must be configured before a program is loaded
+  if((rc = _cmAdIsAudioSysLoaded(p)) != kOkAdRC )
+    return cmErrMsg(&p->err,rc,"The audio system is not configured. Program print failed.");
+
+  // validate the sub-system index arg.
+  if( asSubSysIdx!=cmInvalidIdx && asSubSysIdx >= p->dsSsCnt )
+  {
+    rc = cmErrMsg(&p->err,kInvalidSubSysIdxAdRC,"The sub-system index %i is invalid. Program print failed.",asSubSysIdx);
+    goto errLabel;
+  }
+
+  // for each sub-system
+  for(i=0; i<p->dsSsCnt; ++i)
+    if(  i==asSubSysIdx || asSubSysIdx==cmInvalidIdx )
+    {
+      if( cmDspSysPrintPgm(p->dsSsArray[i].dsH,fn) != kOkDspRC )
+        rc = cmErrMsg(&p->err,kDspSysFailAdRC,"The program print failed.");
+      
+      break;
+    }
+
+ errLabel:
+  return rc;
+}
+
 cmAdRC_t _cmAdReinitAudioSys( cmAd_t* p )
 {
   cmAdRC_t rc = kOkAdRC;
@@ -1294,6 +1324,10 @@ cmAdRC_t cmAudDspReceiveClientMsg( cmAdH_t h, unsigned msgByteCnt, const void* m
       rc = _cmAudDspClientMsgPoll(p);
       break;
 
+    case kPrintPgmDuiId:
+      _cmAudDspPrintPgm(p,m->asSubIdx,cmDsvStrcz(&m->value));
+      break;
+
     default:
       if( cmAudioSysDeliverMsg(p->asH,msg,msgByteCnt,cmInvalidId) != kOkAsRC )
         rc = cmErrMsg(&p->err,kSendMsgFailAdRC,"Message delivery to the audio system failed.");
diff --git a/cmAudDspIF.c b/cmAudDspIF.c
index 297fe37..f938f1c 100644
--- a/cmAudDspIF.c
+++ b/cmAudDspIF.c
@@ -148,15 +148,18 @@ cmAiRC_t _cmAdIfReadCfgFile( cmAi_t* p, cmCtx_t* ctx )
 }
 
 
-cmAiRC_t _cmAdIfSendIntMsg(cmAiH_t h, unsigned selId, unsigned asSubIdx, unsigned flags, unsigned iv, double dv )
+cmAiRC_t _cmAdIfSendIntMsg(cmAiH_t h, unsigned selId, unsigned asSubIdx, unsigned flags, unsigned iv, double dv, const cmChar_t* str )
 {  
   cmAi_t*      p = _cmAiHandleToPtr( h );
   cmDspValue_t v;
 
-  if(iv == cmInvalidIdx )
-    cmDsvSetDouble(&v,dv);
+  if(str != NULL )
+    cmDsvSetStrcz(&v,str);
   else
-    cmDsvSetUInt(&v,iv);
+    if(iv == cmInvalidIdx )
+      cmDsvSetDouble(&v,dv);
+    else
+      cmDsvSetUInt(&v,iv);
  
   if( cmMsgSend(&p->err,asSubIdx,kUiSelAsId,selId,flags,cmInvalidId,cmInvalidId,&v,p->parms.audDspFunc,p->parms.audDspFuncDataPtr) != kOkMsgRC )
     return cmErrMsg(&p->err,kSendFailAiRC,"The integer message sel id:%i value:%i transmission failed.",selId,iv);
@@ -245,25 +248,29 @@ cmAiRC_t       cmAdIfRecvAudDspMsg( cmAiH_t h, unsigned msgByteCnt, const void*
 }
 
 cmAiRC_t        cmAdIfDeviceReport( cmAiH_t h )
-{ return _cmAdIfSendIntMsg(h,kDevReportDuiId,cmInvalidIdx,0,cmInvalidIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kDevReportDuiId,cmInvalidIdx,0,cmInvalidIdx,0.0,NULL); }
  
 cmAiRC_t        cmAdIfSetAudioSysCfg(   cmAiH_t h, unsigned asCfgIdx )
-{ return _cmAdIfSendIntMsg(h,kSetAudioCfgDuiId,cmInvalidIdx,0,asCfgIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kSetAudioCfgDuiId,cmInvalidIdx,0,asCfgIdx,0.0,NULL); }
 
 cmAiRC_t        cmAdIfSetAudioDevice(   cmAiH_t h, unsigned asSubIdx, bool inputFl, unsigned devIdx )
-{ return _cmAdIfSendIntMsg(h,kSetAudioDevDuiId,asSubIdx,inputFl,devIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kSetAudioDevDuiId,asSubIdx,inputFl,devIdx,0.0,NULL); }
 
 cmAiRC_t        cmAdIfSetSampleRate(  cmAiH_t h, unsigned asSubIdx, double srate )
-{ return _cmAdIfSendIntMsg(h,kSetSampleRateDuiId,asSubIdx,0,cmInvalidIdx,srate); }
+{ return _cmAdIfSendIntMsg(h,kSetSampleRateDuiId,asSubIdx,0,cmInvalidIdx,srate,NULL); }
 
 cmAiRC_t        cmAdIfLoadProgram(   cmAiH_t h, unsigned asSubIdx, unsigned pgmIdx )
-{ return _cmAdIfSendIntMsg(h,kSetPgmDuiId,asSubIdx,0,pgmIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kSetPgmDuiId,asSubIdx,0,pgmIdx,0.0,NULL); }
+
+cmAiRC_t        cmAdIfPrintPgm(   cmAiH_t h,unsigned asSubIdx, const cmChar_t* fn )
+{ return _cmAdIfSendIntMsg(h,kPrintPgmDuiId,asSubIdx,0,cmInvalidIdx,0.0,fn); }
+
   
 cmAiRC_t        cmAdIfEnableAudio( cmAiH_t h, bool enableFl )
-{ return _cmAdIfSendIntMsg(h,kEnableDuiId,cmInvalidIdx,enableFl,cmInvalidIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kEnableDuiId,cmInvalidIdx,enableFl,cmInvalidIdx,0.0,NULL); }
 
 cmAiRC_t        cmAdIfEnableStatusNotify( cmAiH_t h, bool enableFl )
-{ return _cmAdIfSendIntMsg(h,kSetNotifyEnableDuiId,cmInvalidIdx,enableFl,cmInvalidIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kSetNotifyEnableDuiId,cmInvalidIdx,enableFl,cmInvalidIdx,0.0,NULL); }
 
 cmAiRC_t        cmAdIfSendMsgToAudioDSP( 
   cmAiH_t             h, 
@@ -287,5 +294,5 @@ cmAiRC_t        cmAdIfSendMsgToAudioDSP(
 
 
 cmAiRC_t        cmAdIfDispatchMsgToHost(  cmAiH_t h ) 
-{ return _cmAdIfSendIntMsg(h,kClientMsgPollDuiId,cmInvalidIdx,0,cmInvalidIdx,0.0); }
+{ return _cmAdIfSendIntMsg(h,kClientMsgPollDuiId,cmInvalidIdx,0,cmInvalidIdx,0.0,NULL); }
 
diff --git a/cmAudDspIF.h b/cmAudDspIF.h
index eae3ba1..df4209d 100644
--- a/cmAudDspIF.h
+++ b/cmAudDspIF.h
@@ -118,6 +118,10 @@ extern "C" {
   // prior to calling this function.
   cmAiRC_t        cmAdIfLoadProgram(    cmAiH_t h, unsigned asSubIdx, unsigned pgmIdx );
 
+  // Print a representation (instances and connections) of the loaded program 
+  // to a JSON file.
+  cmAiRC_t        cmAdIfPrintPgm(   cmAiH_t h, unsigned asSubIdx, const cmChar_t* fn );
+
   // Start the audio streaming. 
   // An audio configuration must have been selected via cmAdIfSetAudioSysCfg()
   // and a DSP program must have been selected via cmAdIfLoadProgram() 
diff --git a/cmMsgProtocol.h b/cmMsgProtocol.h
index f351661..725a76b 100644
--- a/cmMsgProtocol.h
+++ b/cmMsgProtocol.h
@@ -47,6 +47,7 @@ extern "C" {
     kClientMsgPollDuiId,   // Periodic check for and deliver messages waiting in the audio system for delivery to the client. 
     kSendMsgDuiId,         // forward msg to the audio system
     kDevReportDuiId,       // print a device report
+    kPrintPgmDuiId,        // write the currently loaded pgm as a JSON file
 
     kRightAlignDuiId = 0,  // label alignment id used by kLabelDuiId 
     kLeftAlignDuiId,  
diff --git a/dsp/cmDspClass.h b/dsp/cmDspClass.h
index cb7d221..4fa1e2e 100644
--- a/dsp/cmDspClass.h
+++ b/dsp/cmDspClass.h
@@ -177,7 +177,7 @@ extern "C" {
   typedef struct cmDspInst_str
   {
     struct cmDspClass_str* classPtr;  // ptr to class for this instance
-    unsigned               symId;     // optional instance label symbol id
+    unsigned               symId;     // optional unique instance label symbol id
     unsigned               id;        // id is unique among all insts
     unsigned               flags;     // See kXXXInstFl above
     cmDspVar_t*            varArray;  //