Another attempt to document the protocol.

PROTOCOL

@@ -94,15 +94,15 @@ GET_STATUS_REQ (0x0120)
 43 50 4e 50   CPNP 
 01 20         GET_STATUS
 00 00 00 00   SEQUENCE
-00 XX 00 00   status type == Seen 0x00 (via udp) and 0x01/0x02 (via tcp)
+00 XX 00 00   (??? Job ID for TCP?)
 00 00         (no payload)
 
-GET_STATUS_RESP (0x8120) (type 0x00)
-------------------------------------
+GET_STATUS_RESP (0x8120) over UDP
+----------------------------------
 43 50 4e 50   CPNP 
 81 20         GET_STATUS
 00 00 00 00   SEQUENCE
-00 00 00 00   (type 0x00)
+00 00 00 00   (always null)
 02 00         (512-byte payload)
 
 01 01 YY XX 43 61 6e 6f 6e 20 43 50 39 30 30 00  YY paper, XX ribbon. 01 = missing, 04 = ready
@@ -138,14 +138,27 @@ ff ff ff ff 40 00 40 00 40 1f 40 1f d0 04 10 07
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 
-GET_STATUS_RESP (0x8120) (type 0x01 or 0x02)
-------------------------------------
+GET_STATUS_RESP (0x8120) over TCP
+----------------------------------
 43 50 4e 50   CPNP 
 81 20         GET_STATUS
 00 00 00 00   SEQUENCE
-00 01 00 00   (type 0x01 -- or 0x02)
+00 XX 00 00   (seen 0x01 or 0x02 -- maybe job id?)
 00 40         (64-byte payload)
 
+  [ Attempt to decode the details ]
+  
+  00 00 01 10 04 04 00 00 00 00 00 00 00 00 00 00
+  00 00 SS 00 01 00 00 00 XX XX XX XX YY YY YY YY
+  00 90 01 00 00 00 00 00 00 00 00 00 00 00 00 00
+  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
+
+  SS: State. 00 wait/01 flags/02 data req/03 done/04 error
+  XX:  Data req offset (Little endian)
+  YY:  Data req length (Little endian)
+  
+[ Examples of output I've seen ]
+
 00 00 01 10 04 04 00 00 00 00 00 00 00 00 00 00 (??? variation 1)
 00 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00
 00 90 01 00 00 00 00 00 00 00 00 00 00 00 00 00