diff --git a/set_record.py b/set_record.py
index 66773df..1e3f330 100644
--- a/set_record.py
+++ b/set_record.py
@@ -261,7 +261,6 @@ class Filter:
 
             if tagcode not in self.TAGCODE_LUT:
                 self.packets_dropped += 1
-                print("LUT ERR", tagcode)
                 return
 
             tag = self.TAGCODE_LUT[tagcode]
@@ -413,11 +412,13 @@ class VcdSink:
             timestamp = self.timestamp
             # unpack
             for i in range(0,4):
-                char = chr(value >> (i*8) & 0xFF)
-                self.strings[tag][1] += char
+                char = value >> (i*8) & 0xFF
+                if char != 0:
+                    self.strings[tag][1] += chr(char)
             # sub of 1 indicates end of string
             if sub == 1:
                 try:
+                    string = self.strings[tag][1]
                     #print(f"### {timestamp:012X} : {self.varnames[tag]} <= \"{self.strings[tag][1]}\"", flush=True)
                     self.writer.change(self.strings[tag][0], timestamp, self.strings[tag][1])
                 except ValueError:
@@ -515,9 +516,9 @@ def main():
 
     print(" === BEGIN NOISE ===")
     try:
-        while True:
-            for b in sys.stdin.buffer.read(1):
-                packet_filter.process(b)
+        for bstr in sys.stdin.buffer:
+            for b in bstr:
+                petf.process(b)
     except KeyboardInterrupt:
         pass