diff --git a/src/dev/devAoTestAsyn.c b/src/dev/devAoTestAsyn.c
new file mode 100644
index 000000000..0d6b9fab0
--- /dev/null
+++ b/src/dev/devAoTestAsyn.c
@@ -0,0 +1,127 @@
+/* devAoTestAsyn.c */
+/* share/src/dev @(#)devAoTestAsyn.c	1.1     11/8/90 */
+
+/* devAoTestAsyn.c - Device Support Routines for testing asynchronous processing*/
+
+
+#include	<vxWorks.h>
+#include	<types.h>
+#include	<stdioLib.h>
+#include	<wdLib.h>
+
+#include	<alarm.h>
+#include	<cvtTable.h>
+#include	<dbDefs.h>
+#include	<dbAccess.h>
+#include	<recSup.h>
+#include	<devSup.h>
+#include	<link.h>
+#include	<aoRecord.h>
+
+/* Create the dset for devAoTestAsyn */
+long init_record();
+long write_ao();
+struct {
+	long		number;
+	DEVSUPFUN	report;
+	DEVSUPFUN	init;
+	DEVSUPFUN	init_record;
+	DEVSUPFUN	get_ioint_info;
+	DEVSUPFUN	write_ao;
+	DEVSUPFUN	special_linconv;
+}devAoTestAsyn={
+	6,
+	NULL,
+	NULL,
+	init_record,
+	NULL,
+	write_ao,
+	NULL};
+
+/* control block for callback*/
+struct callback {
+	void (*callback)();
+	int priority;
+	struct dbAddr dbAddr;
+	WDOG_ID wd_id;
+	void (*process)();
+};
+void callbackRequest();
+
+static void myCallback(pcallback)
+    struct callback *pcallback;
+{
+    struct aoRecord *pao=(struct aoRecord *)(pcallback->dbAddr.precord);
+
+    dbScanLock(pao);
+    (pcallback->process)(&pcallback->dbAddr);
+    dbScanUnlock(pao);
+}
+    
+    
+
+static long init_record(pao,process)
+    struct aoRecord	*pao;
+    void (*process)();
+{
+    char message[100];
+    struct callback *pcallback;
+
+    /* ao.out must be a CONSTANT*/
+    switch (pao->out.type) {
+    case (CONSTANT) :
+	pcallback = (struct callback *)(calloc(1,sizeof(struct callback)));
+	pao->dpvt = (caddr_t)pcallback;
+	pcallback->callback = myCallback;
+	pcallback->priority = priorityLow;
+	if(dbNameToAddr(pao->name,&(pcallback->dbAddr))) {
+		logMsg("dbNameToAddr failed in init_record for devAoTestAsyn\n");
+		exit(1);
+	}
+	pcallback->wd_id = wdCreate();
+	pcallback->process = process;
+	pao->val = pao->inp.value.value;
+	break;
+    default :
+	strcpy(message,pao->name);
+	strcat(message,": devAoTestAsyn (init_record) Illegal OUT field");
+	errMessage(S_db_badField,message);
+	return(S_db_badField);
+    }
+    return(0);
+}
+
+static long write_ao(pao)
+    struct aoRecord	*pao;
+{
+    char message[100];
+    long status,options,nRequest;
+    struct callback *pcallback=(struct callback *)(pao->dpvt);
+    int		wait_time;
+
+    /* ao.out must be a CONSTANT*/
+    switch (pao->out.type) {
+    case (CONSTANT) :
+	if(pao->pact) {
+		printf("%s Completed\n",pao->name);
+		return(0); /* don`t convert*/
+	} else {
+		wait_time = (int)(pao->val * vxTicksPerSecond);
+		if(wait_time<=0) return(0);
+		printf("%s Starting asynchronous processing\n",pao->name);
+		wdStart(pcallback->wd_id,wait_time,callbackRequest,pcallback);
+		return(1);
+	}
+    default :
+	if(pao->nsev<MAJOR_ALARM) {
+		pao->nsev = MAJOR_ALARM;
+		pao->nsta = SOFT_ALARM;
+		if(pao->stat!=SOFT_ALARM) {
+			strcpy(message,pao->name);
+			strcat(message,": devAoTestAsyn (read_ao) Illegal OUT field");
+			errMessage(S_db_badField,message);
+		}
+	}
+    }
+    return(0);
+}