diff --git a/src/dev/devAiDvx2502.c b/src/dev/devAiDvx2502.c
index 6612a5bf9..8ecf2c08e 100644
--- a/src/dev/devAiDvx2502.c
+++ b/src/dev/devAiDvx2502.c
@@ -32,6 +32,7 @@
  * -----------------
  * .01  11-11-91        jba     Moved set of alarm stat and sevr to macros
  * .02  12-02-91        jba     Added cmd control to io-interrupt processing
+ * .03  12-12-91        jba     Set cmd to zero in io-interrupt processing
  * 	...
  */
 
@@ -114,6 +115,7 @@ static long get_ioint_info(cmd,pai,io_type,card_type,card_number)
     short               *card_type;
     short               *card_number;
 {
+    *cmd=0;
     if(pai->inp.type != VME_IO) return(S_dev_badInpType);
     *io_type = IO_AI;
     *card_type = DVX2502;
diff --git a/src/dev/devAiXy566DiL.c b/src/dev/devAiXy566DiL.c
index 826dcf498..f58070324 100644
--- a/src/dev/devAiXy566DiL.c
+++ b/src/dev/devAiXy566DiL.c
@@ -32,6 +32,7 @@
  * -----------------
  * .01  11-11-91        jba     Moved set of alarm stat and sevr to macros
  * .02  12-02-91        jba     Added cmd control to io-interrupt processing
+ * .03  12-12-91        jba     Set cmd to zero in io-interrupt processing
  *      ...
  */
 
@@ -112,6 +113,7 @@ static long get_ioint_info(cmd,pai,io_type,card_type,card_number)
     short               *card_type;
     short               *card_number;
 {
+    *cmd=0;
     if(pai->inp.type != VME_IO) return(S_dev_badInpType);
     *io_type = IO_AI;
     *card_type = XY566DIL;
diff --git a/src/dev/devWfJoergerVtr1.c b/src/dev/devWfJoergerVtr1.c
index fdf041408..c6dbf70c1 100644
--- a/src/dev/devWfJoergerVtr1.c
+++ b/src/dev/devWfJoergerVtr1.c
@@ -32,6 +32,7 @@
  * -----------------
  * .01  11-11-91        jba     Moved set of alarm stat and sevr to macros
  * .02  12-02-91        jba     Added cmd control to io-interrupt processing
+ * .03  12-12-91        jba     Set cmd to zero in io-interrupt processing
  *      ...
  */
 
@@ -120,6 +121,7 @@ static long get_ioint_info(cmd,pwf,io_type,card_type,card_number)
     short               *card_type;
     short               *card_number;
 {
+    *cmd=0;
     if(pwf->inp.type != VME_IO) return(S_dev_badInpType);
     *io_type = IO_WF;
     *card_type = JGVTR1;
diff --git a/src/rec/recTimer.c b/src/rec/recTimer.c
index 0e8593190..716c39e26 100644
--- a/src/rec/recTimer.c
+++ b/src/rec/recTimer.c
@@ -43,6 +43,7 @@
  * .10  10-15-90	mrk	extensible record and device support
  * .11  11-11-91        jba     Moved set and reset of alarm stat and sevr to macros
  * .12  12-02-91        jba     Added cmd control to io-interrupt processing
+ * .13  12-12-91        jba     Set cmd to zero in io-interrupt processing
  */
 
 #include	<vxWorks.h>
@@ -112,6 +113,7 @@ static long get_ioint_info(cmd,ptimer,io_type,card_type,card_number)
     short               *card_type;
     short               *card_number;
 {
+    *cmd=0;
     if(ptimer->out.type != VME_IO) return(S_dev_badInpType);
     *io_type = IO_TIMER;
     if(ptimer->dtyp==0)