diff --git a/artiq/sim/devices.py b/artiq/sim/devices.py
index 3e2295bf6..18b997b69 100644
--- a/artiq/sim/devices.py
+++ b/artiq/sim/devices.py
@@ -93,7 +93,7 @@ class WaveOutput:
 
     @kernel
     def pulse(self, frequency, duration):
-        time.manager.event(("pulse", self.name, frequency, duration))
+        time.manager.event(("pulse", self.name, frequency, self.core.seconds_to_mu(duration)))
         delay(duration)
 
 
diff --git a/artiq/sim/time.py b/artiq/sim/time.py
index 676966735..7fa93d891 100644
--- a/artiq/sim/time.py
+++ b/artiq/sim/time.py
@@ -62,7 +62,7 @@ class Manager:
         r = ""
         prev_time = 0*s
         for time, description in sorted(self.timeline, key=itemgetter(0)):
-            r += "@{:.9f} (+{:.9f}) ".format(time, time-prev_time)
+            r += "{:35}".format("@{:.9f} (+{:.9f}) ".format(time, time-prev_time))
             for item in description:
                 r += "{:16}".format(str(item))
             r += "\n"