diff --git a/src/nwconn.c b/src/nwconn.c
index f5d21e8..96b2d1e 100644
--- a/src/nwconn.c
+++ b/src/nwconn.c
@@ -579,10 +579,22 @@ static int handle_ncp_serv(void)
       } 
       break;
 
-      case 0x13 : { /* Get connection ?? */
-        /* TODO !!!!!!! */
-        *responsedata=(uint8) act_connection;
-        data_len = 1;
+      case 0x13 : { /* Get Station Number */
+        /*
+         * This is the old one-byte connection number call used by
+         * DOS requesters before the richer NCP 23 connection services.
+         * The SDK describes the client-visible API as
+         * NWGetConnectionNumber(); older low-level documentation names the
+         * underlying simple NCP 0x13 "Get Station Number".
+         */
+        if (act_connection > 0 && act_connection < 256) {
+          *responsedata=(uint8) act_connection;
+          data_len = 1;
+        } else {
+          XDPRINTF((1, 0, "Get Station Number failed, conn=%d",
+                    act_connection));
+          completition = 0xff;
+        }
       } 
       break;