diff --git a/UI/display.c b/UI/display.c
index 4fb6043..bb1371a 100644
--- a/UI/display.c
+++ b/UI/display.c
@@ -21,6 +21,7 @@
 #include "serial.h"
 #include <math.h>
 #include <stdlib.h>
+#include <string.h>
 
 GtkWidget *window;
 GdkPixbuf *pixbuf;
@@ -77,6 +78,22 @@ gboolean prescaler_changed(GtkWidget *widget)
 	serial_set_prescaler(base);
 	return TRUE;
 }
+gboolean vref_changed(GtkWidget *widget)
+{
+	unsigned char base;
+	gchar *c = gtk_combo_box_get_active_text(GTK_COMBO_BOX(widget));
+
+	/* Ugly :) */
+	if (!strcmp(c,"AREF")) {
+		base=0;
+	} else if (!strcmp(c,"AVcc")) {
+		base=1;
+	} else {
+		base = 3;
+	}
+	serial_set_vref(base);
+	return TRUE;
+}
 
 int main(int argc,char **argv)
 {
@@ -134,6 +151,17 @@ int main(int argc,char **argv)
 	gtk_combo_box_append_text(GTK_COMBO_BOX(scale),"2");
 	gtk_combo_box_set_active(GTK_COMBO_BOX(scale),0);
 
+	hbox = gtk_hbox_new(FALSE,4);
+	gtk_box_pack_start(GTK_BOX(vbox),hbox,TRUE,TRUE,0);
+	gtk_box_pack_start(GTK_BOX(hbox),gtk_label_new("VRef source:"),TRUE,TRUE,0);
+	scale=gtk_combo_box_new_text();
+	gtk_box_pack_start(GTK_BOX(hbox),scale,TRUE,TRUE,0);
+	g_signal_connect(G_OBJECT(scale),"changed",G_CALLBACK(&vref_changed),NULL);
+
+	gtk_combo_box_append_text(GTK_COMBO_BOX(scale),"AREF");
+	gtk_combo_box_append_text(GTK_COMBO_BOX(scale),"AVcc");
+	gtk_combo_box_append_text(GTK_COMBO_BOX(scale),"Internal 1.1V");
+
 	scope_display_set_data(image,data,sizeof(data));
 
 	gtk_widget_show_all(window);
diff --git a/oscope.pde b/oscope.pde
index cf043a6..b9d102c 100644
--- a/oscope.pde
+++ b/oscope.pde
@@ -44,7 +44,7 @@ unsigned char dataBuffer[NUM_SAMPLES];
 unsigned short dataBufferPtr;
 unsigned char triggerLevel=0;
 unsigned char triggerFlags=0;
-unsigned char autoTrigSamples = 100;
+unsigned short autoTrigSamples = 512;
 unsigned char holdoffSamples = 0;
 
 /* Booleans merged */
@@ -233,7 +233,7 @@ void loop() {
 ISR(ADC_vect)
 {
 	static unsigned char last=0;
-	static unsigned char autoTrigCount=0;
+	static unsigned short autoTrigCount=0;
 	static boolean do_store_data;
 	static unsigned char holdoff;