diff --git a/lambda/command.c b/lambda/command.c
index fcd9d56..205f33e 100644
--- a/lambda/command.c
+++ b/lambda/command.c
@@ -96,13 +96,17 @@
 		}
 		beep(1, length, tone);
 	}
-	else if (simulation) {
+	else if (strcmp_P(fields[4], PSTR("!")) == 0 && simulation) {
+		// add one second per measurement to the timebase,
+		// assuming one measurement was logged per second
+		addInts(INTS_PER_SEC);
 		Measurement meas = readMeas(fields, fieldCount);
 		if (getHeatingState() == HEATING_OFF ||
 				getHeatingState() == HEATING_READY) {
 			updateMeas(meas);
 		}
 		reason(meas);
+		updateDisplayIfPending();
 	}
 }
 
diff --git a/lambda/interrupts.c b/lambda/interrupts.c
index 7e89b81..cb8b1fc 100644
--- a/lambda/interrupts.c
+++ b/lambda/interrupts.c
@@ -13,6 +13,7 @@
 #include <avr/interrupt.h>
 #include <avr/sleep.h>
 #include <util/atomic.h>
+#include "command.h"
 #include "interrupts.h"
 #include "sensors.h"
 #include "display.h"
@@ -25,7 +26,9 @@
  * Called about every 16.4 ms.
  */
 ISR(TIMER0_OVF_vect) {
-	ints++;
+	if (! isSimulation()) {
+		ints++;
+	}
 	oscillateBeep();
 	if (bit_is_clear(PINB, PB0) && ! buttonPressed) {
 		buttonPressed = true;
@@ -43,6 +46,12 @@
 	return atomicInts;
 }
 
+void addInts(uint8_t const add) {
+	ATOMIC_BLOCK(ATOMIC_FORCEON) {
+		ints += add;
+	}
+}
+
 uint32_t getTime(void) {
 	return getInts() / INTS_PER_SEC;
 }
diff --git a/lambda/interrupts.h b/lambda/interrupts.h
index 2a5c580..8b7c6cb 100644
--- a/lambda/interrupts.h
+++ b/lambda/interrupts.h
@@ -21,6 +21,12 @@
 uint32_t getInts(void);
 
 /**
+ * Adds the given number of interrupts to the interrupt counter
+ * used as timebase. Useful only for simulation.
+ */
+void addInts(uint8_t add);
+
+/**
  * Returns the time in about seconds since last reset.
  */
 uint32_t getTime(void);
diff --git a/lambda/lambda.c b/lambda/lambda.c
index ed8e528..31204eb 100644
--- a/lambda/lambda.c
+++ b/lambda/lambda.c
@@ -70,12 +70,14 @@
 			}
 			reason(meas);
 		}
+		if (! isSimulation()) {
+			updateDisplayIfPending();
+		}
 		if (isUSARTReceived()) {
 			char data[64];
 			getUSARTData(data, sizeof(data));
 			runCommand(data);
 		}
-		updateDisplayIfPending();
 	}
 
 	// never reached
diff --git a/lambda/sensors.c b/lambda/sensors.c
index b084d6d..13768f3 100644
--- a/lambda/sensors.c
+++ b/lambda/sensors.c
@@ -195,7 +195,6 @@
 	} else {
 		PORTB &= ~(1 << PB2);
 		heatingState = HEATING_OFF;
-		// cancelAlert(true);
 	}
 }