diff --git a/VAX/vax_cpu.c b/VAX/vax_cpu.c
index 827276d2..99e12845 100644
--- a/VAX/vax_cpu.c
+++ b/VAX/vax_cpu.c
@@ -2582,10 +2582,12 @@ for ( ;; ) {
         else if (cpu_unit.flags & UNIT_CONH)            /* halt to console? */
             cc = con_halt (CON_HLTINS, cc);             /* enter firmware */
         else {
-            /* allow potentially pending console output to */
-            /* be displayed before dropping back to scp */
-            if (sim_interval <= SERIAL_OUT_WAIT) {
-                sim_interval -= SERIAL_OUT_WAIT;
+            /* allow potentially pending I/O (console output, 
+               or other devices) to complete before dropping 
+               back to scp */
+            while ((sim_clock_queue != QUEUE_LIST_END) &&
+                   ((sim_clock_queue->flags & UNIT_IDLE) == 0)) {
+                sim_interval = 0;
                 temp = sim_process_event ();
                 if (temp)
                     ABORT (temp);