diff --git a/calibrate.py b/calibrate.py
new file mode 100644
index 0000000..a95b02c
--- /dev/null
+++ b/calibrate.py
@@ -0,0 +1,17 @@
+from driver import protocol, tef
+import os, time
+
+DEVICE = os.getenv("DEV") or "COM6"
+CLOCK_ENV = os.getenv("CLK", "").strip().lower() or "dp"
+if CLOCK_ENV == "dp": CLOCK = 12000000 # DP-666
+elif CLOCK_ENV == "x": CLOCK = 9216000
+else: CLOCK = int(CLOCK_ENV)
+
+p = protocol.I2CPCClient(DEVICE)
+
+with tef.TEF6686(p) as tf:
+    tf.init(clock=CLOCK)
+    tf.AUDIO_Set_WaveGen(5, 0, 0, 400)
+    tf.AUDIO_Set_Input(240)
+    tf.AUDIO_Set_Mute(False)
+    while True: time.sleep(0.1)
\ No newline at end of file
diff --git a/xrd.py b/xrd.py
index e7b26c5..012919a 100644
--- a/xrd.py
+++ b/xrd.py
@@ -25,10 +25,14 @@ DEVICE = os.getenv("DEV") or "COM6"
 FREQ_NOT_ALLOWED_RANGE = []
 
 PASSWORD = os.getenv("PW") or "test"
-CLOCK = 12000000 # DP-666
+
+CLOCK_ENV = os.getenv("CLK", "").strip().lower() or "dp"
+if CLOCK_ENV == "dp": CLOCK = 12000000 # DP-666
+elif CLOCK_ENV == "x": CLOCK = 9216000
+else: CLOCK = int(CLOCK_ENV)
 
 SALT_LENGTH = 16
-SS_UPDATE_INTERVAL = 0.115
+SS_UPDATE_INTERVAL = 0.095
 RDS_UPDATE_INTERVAL = 0.086
 
 def freq_allowed(freq: int):
@@ -59,7 +63,7 @@ def authenticate(conn: socket.socket):
 
     while True:
         try:
-            data = conn.recv(1024)
+            data = conn.recv(len(expected_hash))
             if not data: return False
             if data.strip() == expected_hash.strip(): return True
         except BlockingIOError:
@@ -280,4 +284,6 @@ def run_server():
                             run_periodic(tef, conn, state)
                             time.sleep(0.025)
 
-if __name__ == "__main__": run_server()
\ No newline at end of file
+if __name__ == "__main__": 
+    try: run_server()
+    except Exception: pass
\ No newline at end of file