diff --git a/scripts/submit_job.py b/scripts/submit_job.py
index ac81d1e..41d7940 100755
--- a/scripts/submit_job.py
+++ b/scripts/submit_job.py
@@ -5,6 +5,7 @@ import subprocess
 import tempfile
 import os
 import time
+import socket
 
 # Force temp files into a folder inside your project (fully owned by you)
 custom_temp_dir = os.path.join(os.getcwd(), "tmp")
@@ -17,6 +18,32 @@ MVSHOST = "oldcomputernerd.com"
 RDRPORT = 3505
 MVS_PASSWORD = os.environ.get("MVS_BATCH_PASSWORD")
 
+def wait_for_port(host, port, timeout=30, poll_interval=1):
+    """Wait for port to become available (not in use)"""
+    print(f"Waiting for port {port} on {host} to be ready...")
+    start_time = time.time()
+
+    while time.time() - start_time < timeout:
+        try:
+            # Try to connect - if successful, port is available
+            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            sock.settimeout(2)
+            result = sock.connect_ex((host, port))
+            sock.close()
+
+            if result == 0:
+                print(f"Port {port} is ready")
+                return True
+            else:
+                print(f"Port {port} not responding (error {result}), waiting...")
+                time.sleep(poll_interval)
+        except socket.error as e:
+            print(f"Socket error: {e}, retrying...")
+            time.sleep(poll_interval)
+
+    print(f"Timeout waiting for port {port} to be ready after {timeout}s")
+    return False
+
 
 def create_jcl_payload(local_file, dataset_name, member_name): 
     
@@ -171,9 +198,10 @@ if __name__ == "__main__":
     if upload_source(local_file, dataset_name, member_name, mvshost) != 0:
         sys.exit(1)
 
-    # Wait between submissions to avoid overwhelming the card reader
-    print("Waiting 3 seconds before submitting compile job...")
-    time.sleep(3)
+    # Wait for card reader port to be ready before submitting compile job
+    if not wait_for_port(mvshost, RDRPORT, timeout=30):
+        print(f"Error: Card reader port {RDRPORT} not available")
+        sys.exit(1)
 
     # Step 2: Submit JCL job
     exit_code = submit_jcl(job, mvshost)