diff --git a/unit_tests/logicdata.cpp b/unit_tests/logicdata.cpp
index eb60229b77..e278c2575b 100644
--- a/unit_tests/logicdata.cpp
+++ b/unit_tests/logicdata.cpp
@@ -58,19 +58,11 @@ static void writeAs(int64_t value, int numBytes) {
 	} else {
 		writeByte(numBytes);
 		for (int i = 0; i < numBytes; i++) {
-			writeByte((uint8_t)((value >> (i * 8)) & 0xff));
+			writeByte((uint8_t) ((value >> (i * 8)) & 0xff));
 		}
 	}
 }
 
-static void writeString(const char *value) {
-	int len = strlen(value);
-	writeByte(len);
-	for (int i = 0; i < len; i++) {
-		writeByte(value[i]);
-	}
-}
-
 // This is the main secret of this format! :)
 static void write(int64_t value) {
 	if (value < 0 || value > 0xFFFFFFFFL) {
@@ -88,6 +80,14 @@ static void write(int64_t value) {
 	}
 }
 
+static void writeString(const char *value) {
+	int len = strlen(value);
+	write(len);
+	for (int i = 0; i < len; i++) {
+		writeByte(value[i]);
+	}
+}
+
 // todo: some C++ magic would allow us to drop 'count' parameter
 // todo: Look at efi::size in util
 static void write(int values[], int count) {
@@ -138,16 +138,31 @@ static void writeHeader() {
 
 }
 
+static void writeDouble(double value) {
+	static_assert(sizeof(double) == 8);
+
+	if (value == 0.0) {
+		writeByte(0);
+	} else {
+		writeByte(8);
+		char *ptr = (char*) (void*) &value;
+
+		for (int i = 0; i < 8; i++) {
+			writeByte(ptr[i]);
+		}
+	}
+}
+
 static void writeChannelHeader(int ch) {
 	write(0xff);
 	write(ch);
 	writeString(channelNames[ch]);
 	write(0, 2);
-	write(1.0);
+	writeDouble(1.0);
 	write(0);
-	write(0.0);
+	writeDouble(0.0);
 	write(1);	// or 2
-	write(0.0);	// or 1.0
+	writeDouble(0.0);	// or 1.0
 
 	// this part sounds like the 'next' pointer?
 	if (ch == numChannels - 1) {
@@ -167,11 +182,11 @@ static void writeEdges(int64_t *chDeltas, bool useLongDeltas, int numEdges) {
 		// set 16-bit 'sign' flag
 		if (!useLongDeltas && (d & SIGN_FLAG) == SIGN_FLAG)
 			d = (d & 0x7fff) | (SIGN_FLAG >> 16);
-		writeByte((uint8_t)(d & 0xff));
-		writeByte((uint8_t)((d >> 8) & 0xff));
+		writeByte((uint8_t) (d & 0xff));
+		writeByte((uint8_t) ((d >> 8) & 0xff));
 		if (useLongDeltas) {
-			writeByte((uint8_t)((d >> 16) & 0xff));
-			writeByte((uint8_t)((d >> 24) & 0xff));
+			writeByte((uint8_t) ((d >> 16) & 0xff));
+			writeByte((uint8_t) ((d >> 24) & 0xff));
 		}
 	}
 	writeByte(0x00);
@@ -197,6 +212,7 @@ static void writeChannelData(int ch, int64_t *chDeltas, int chLastState,
 	write(ch + 1);
 	write(0);
 	write(realDurationInSamples);
+	printf("realDurationInSamples=%d\n", realDurationInSamples);
 	write(1);
 	write(lastRecord);
 
@@ -417,9 +433,9 @@ static void writeEvents(CompositeEvent *events, int count) {
 				prevTs = ts;
 				chPrevState = chState;
 			}
-			writeChannelData(ch, chDeltas, chPrevState, prevTs, useLongDeltas,
-					deltaCount);
 		}
+		writeChannelData(ch, chDeltas, chPrevState, prevTs, useLongDeltas,
+				deltaCount);
 	}
 
 	free(chDeltas);
@@ -458,7 +474,7 @@ static void writeFooter() {
 
 	write(BLOCK);
 	write(0);
-	write(1.0);
+	writeDouble(1.0);
 	write(SUB);
 	write(0, 6);
 	write(1);