fix(protocol): improve terminator frame detection in write_blastware_file.

fix: rename .n00 to just blastware file (.n00 was false positive)

minimateplus/blastware_file.py

@@ -2,7 +2,7 @@
 blastware_file.py — Blastware binary file codec for bidirectional interoperability.
 
 Reads and writes the proprietary Instantel/Blastware file formats:
-  .N00 / .9T0 / .EI0 / etc.  — Waveform event (extension encoding UNKNOWN — see below)
+  Waveform events (.CE0W, .VM0H, .440, .7M0, etc.) (extension encoding UNKNOWN — see below)
   .MLG                        — Monitor log (monitoring session history)
 
 All waveform formats share a common 22-byte file header prefix and identical
@@ -28,7 +28,7 @@ EXTENSION ENCODING — V10.72 firmware FULLY CONFIRMED 2026-04-22:
 
 ─── File structure overview ─────────────────────────────────────────────────────
 
-N00 (single-shot waveform, confirmed from example-events/4-3-26-multi/M529LIY6.N00):
+Waveform file structure (confirmed from example-events/4-3-26-multi/M529LIY6 (example event)):
 
   [22B header] [21B STRT record] [body bytes] [26B footer]
 
@@ -36,7 +36,7 @@ N00 (single-shot waveform, confirmed from example-events/4-3-26-multi/M529LIY6.N
     10 00 01 80 00 00  — fixed prefix
     49 6e 73 74 61 6e 74 65 6c 00  — b'Instantel\x00'
     07 2c              — fixed
-    00 12 03 00        — N00 type marker
+    00 12 03 00        — waveform file type tag (shared by all waveform extensions)
 
   STRT record (21 bytes, immediately follows header):
     53 54 52 54  — b'STRT'
@@ -84,10 +84,10 @@ MLG (monitor log, confirmed from example-events/4-3-26-multi/BE11529.MLG):
 
 ─── Critical implementation notes ──────────────────────────────────────────────
 
-N00 body reconstruction algorithm (confirmed 2026-04-21 from verification against
+Waveform body reconstruction algorithm (confirmed 2026-04-21 from verification against
-M529LIY6.N00 using raw_s3_20260403_153508.bin capture):
+M529LIY6 (example event) using raw_s3_20260403_153508.bin capture):
 
-  The N00 body bytes come from the A5 frame content, stripped of DLE-framing
+  The waveform body bytes come from the A5 frame content, stripped of DLE-framing
   artifacts.  Each A5 frame contributes a different slice of its data section,
   with DLE+{0x02,0x03,0x04} byte pairs stripped.
 
@@ -136,8 +136,8 @@ MLG CRC:
       All waveform extensions share the same binary format — the extension is set
       by blastware_filename() based on the event timestamp and type.
 
-  read_n00(path) → Event
+  read_blastware_file(path) → Event
-      Parse a .N00 file into an Event object with waveform data populated.
+      Parse a Blastware waveform file into an Event object with waveform data populated.
       (Not yet implemented — placeholder raises NotImplementedError.)
 
   write_mlg(entries, serial, path)
@@ -160,7 +160,7 @@ from .models import Event, MonitorLogEntry, Timestamp
 
 # ── File header constants ─────────────────────────────────────────────────────
 
-# Common 16-byte prefix shared by N00 and MLG (confirmed from binary inspection).
+# Common 16-byte prefix shared by waveform files and MLG (confirmed from binary inspection).
 _FILE_HEADER_PREFIX = bytes.fromhex("1000018000004973") + b"tantel\x00\x07\x2c"
 # = 10 00 01 80 00 00 49 73 74 61 6e 74 65 6c 00 07 2c  (17 bytes)
 # Confirmed breakdown: 10 00 01 80 00 00 = fixed; "Instantel\x00" = 10B; 07 2c = fixed
@@ -169,19 +169,19 @@ _FILE_HEADER_PREFIX = bytes.fromhex("1000018000004973") + b"tantel\x00\x07\x2c"
 _FILE_HEADER_PREFIX = b"\x10\x00\x01\x80\x00\x00Instantel\x00\x07\x2c"  # 17 bytes
 
 # Waveform file type tag (4 bytes after common prefix) — shared by ALL waveform extensions
-_N00_TYPE_TAG = b"\x00\x12\x03\x00"   # confirmed from M529LIY6.N00 — same tag for .CE0W, .VM0H, etc.
+_WAVEFORM_TYPE_TAG = b"\x00\x12\x03\x00"   # confirmed from M529LIY6 (example event) — same tag for .CE0W, .VM0H, etc.
 
 # MLG type tag (4 bytes after common prefix)
 _MLG_TYPE_TAG = b"\x22\x01\x0e\xa0"   # confirmed from BE11529.MLG  offset 0x11..0x14
 
 # Total header sizes
-_N00_HEADER_SIZE = 22    # 17 + 4 = 21... wait. Let me recalculate.
+_WAVEFORM_HEADER_SIZE = 22    # 17 + 4 = 21... wait. Let me recalculate.
 # From binary: first 22 bytes = header, then STRT at byte 22.
 # 17-byte common prefix + 4-byte type tag = 21 bytes. But observed header is 22B.
 # Checking: 6 fixed + 10 "Instantel\x00" + 2 "07 2c" = 18B prefix, then 4B type tag = 22B.
 # Re-count: b"\x10\x00\x01\x80\x00\x00" = 6B + b"Instantel\x00" = 10B + b"\x07\x2c" = 2B = 18B prefix.
 _FILE_HEADER_PREFIX = b"\x10\x00\x01\x80\x00\x00Instantel\x00\x07\x2c"  # 18 bytes
-_N00_HEADER_SIZE = 22    # 18 + 4 = 22 bytes ✅
+_WAVEFORM_HEADER_SIZE = 22    # 18 + 4 = 22 bytes ✅
 _MLG_HEADER_SIZE = 308   # confirmed from BE11529.MLG
 
 # MLG record marker (4 bytes after 2-byte CRC at start of each record)
@@ -201,10 +201,10 @@ def _encode_ts_be(ts: Optional[datetime.datetime]) -> bytes:
     """
     Encode a datetime as an 8-byte big-endian Blastware timestamp.
 
-    Format (N00 and MLG record timestamps):
+    Format (waveform file and MLG record timestamps):
       [day][month][year_HI][year_LO][0x00][hour][min][sec]
 
-    Big-endian year confirmed from M529LIY6.N00 footer:
+    Big-endian year confirmed from M529LIY6 (example event) footer:
       footer bytes [2..9] = 01 04 07 ea 00 00 1c 08
       → day=1 month=4 year=0x07ea=2026 hour=0 min=28 sec=8  ✅
 
@@ -270,7 +270,7 @@ def _strip_inner_frame_dles(data: bytes) -> bytes:
 
     Lone 0x10 bytes not followed by {0x02, 0x03, 0x04} are kept as-is.
 
-    Confirmed correct by verifying reconstructed N00 body against M529LIY6.N00:
+    Confirmed correct by verifying reconstructed waveform body against M529LIY6 (example event):
       - 0x10 0x02 in terminator → 0x02 kept ✓
       - 0x10 0x04 in terminator (month byte) → 0x04 kept ✓
     """
@@ -290,14 +290,14 @@ def _strip_inner_frame_dles(data: bytes) -> bytes:
 
 def _frame_body_bytes(frame: S3Frame, skip: int) -> bytes:
     """
-    Extract the N00 body contribution from one A5 S3Frame.
+    Extract the waveform body contribution from one A5 S3Frame.
 
     The contribution is frame.data[skip:] with inner-frame DLE pairs stripped
     per _strip_inner_frame_dles().  The chk_byte is temporarily appended before
     stripping to handle the split-pair edge case where a DLE at the end of
     frame.data is paired with chk_byte.
 
-    Split-pair edge case (confirmed for A5[8] of M529LIY6.N00, 2026-04-21):
+    Split-pair edge case (confirmed for A5[8] of M529LIY6 (example event), 2026-04-21):
 
     S3FrameParser appends DLE+XX pairs as two literal bytes when XX ∉ {DLE, ETX}.
     When the LAST occurrence of such a pair straddles the payload/checksum boundary
@@ -319,7 +319,7 @@ def _frame_body_bytes(frame: S3Frame, skip: int) -> bytes:
         skip:  Number of leading bytes in frame.data to exclude (frame header).
 
     Returns:
-        bytes — the N00 body contribution for this frame.
+        bytes — the waveform body contribution for this frame.
     """
     if skip >= len(frame.data):
         return b""
@@ -383,10 +383,10 @@ _STEM_CHARS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
 #     S353L4H0.9X0W  Full Waveform   2025-06-23 14:01:09  AB=9X=357  ✓
 #
 # OLD FIRMWARE (S338, 3-char extensions ending in '0') — UNKNOWN:
-#   Observed: .N00, .9T0, .EI0, .490, .5K0, .980, .ML0
+#   Observed (old firmware / manual downloads): .440, .470, .7M0, .9T0, .EI0, etc.
 #   The V10.72 formula does NOT apply to these.
 #   Extension is NOT recording mode (refuted 2026-04-21: continuous → .EI0, not .9T0).
-#   blastware_filename() returns .N00 as a placeholder for old-firmware units.
+#   blastware_filename() computes the correct AB0 extension for V10.72 firmware.
 #
 # WRONG earlier assumption (do not re-introduce):
 #   Extension was believed to encode recording mode × sample rate.
@@ -502,15 +502,15 @@ def blastware_filename(event: Event, serial: str, ach: bool = False) -> str:
     return prefix + stem + ext
 
 
-# ── N00 file writer ───────────────────────────────────────────────────────────
+# ── Waveform file writer ───────────────────────────────────────────────────────────
 
-def write_n00(
+def write_blastware_file(
     event: Event,
     a5_frames: list[S3Frame],
     path: Union[str, Path],
 ) -> None:
     """
-    Write a Blastware .N00 waveform file from a downloaded event.
+    Write a Blastware waveform file from a downloaded event.
 
     Args:
         event:     Event object (populated by get_events() or download_waveform()).
@@ -520,7 +520,7 @@ def write_n00(
                    read_bulk_waveform_stream() when collecting frames.
                    Must have at least 2 frames (probe + terminator).
         path:      Destination file path.  Parent directory must exist.
-                   Extension is not enforced — caller should use ".N00".
+                   Extension should be set via blastware_filename().
 
     File layout:
         [22B header] [21B STRT] [body bytes] [26B footer]
@@ -529,7 +529,7 @@ def write_n00(
         ValueError: if a5_frames is empty or has no terminator (page_key=0).
         OSError: if the file cannot be written.
 
-    Confirmed correct N00 body reconstruction against M529LIY6.N00 (2026-04-21).
+    Confirmed correct waveform body reconstruction against M529LIY6 (example event) (2026-04-21).
     """
     if not a5_frames:
         raise ValueError("a5_frames must not be empty")
@@ -538,11 +538,11 @@ def write_n00(
 
     # ── Extract STRT record from probe frame ────────────────────────────────
     # The STRT record (21 bytes) lives verbatim inside A5[0].data[7:].
-    # It is stored as-is in the N00 file — do NOT reconstruct it from Event
+    # It is stored as-is in the waveform file — do NOT reconstruct it from Event
     # fields, as bytes [10:14] and [14:20] contain device-specific values
     # (not simply key4 repeated or zero-padded).  Confirmed 2026-04-21.
     #
-    # STRT layout (21 bytes, observed in M529LIY6.N00):
+    # STRT layout (21 bytes, observed in M529LIY6 files):
     #   [0:4]   b'STRT'
     #   [4:6]   0xff 0xfe (fixed)
     #   [6:10]  key4 (event key)
@@ -556,7 +556,7 @@ def write_n00(
     # Blastware file stores the stripped form, so we must strip before extracting.
     #
     # Example (M529LK0Y, 2026-04-21): STRT contains value 0x02 encoded as [10 02]
-    # on the wire.  Without stripping, STRT is 22 raw bytes → write_n00 writes the
+    # on the wire.  Without stripping, STRT is 22 raw bytes → write_blastware_file writes the
     # DLE prefix into the file AND begins the body 1 byte too early (probe_skip off
     # by 1).  Stripping fixes both.
     #
@@ -594,28 +594,39 @@ def write_n00(
     if len(strt) != 21:
         raise ValueError(f"STRT record must be 21 bytes, got {len(strt)}")
 
-    # ── Build N00 header ─────────────────────────────────────────────────────
+    # ── Build waveform file header ─────────────────────────────────────────────────────
-    header = _FILE_HEADER_PREFIX + _N00_TYPE_TAG
+    header = _FILE_HEADER_PREFIX + _WAVEFORM_TYPE_TAG
-    assert len(header) == _N00_HEADER_SIZE, f"N00 header must be {_N00_HEADER_SIZE} bytes"
+    assert len(header) == _WAVEFORM_HEADER_SIZE, f"Waveform header must be {_WAVEFORM_HEADER_SIZE} bytes"
 
     # ── Build body from A5 frames ────────────────────────────────────────────
-    # The N00 body is reconstructed from ALL A5 frames (data + terminator).
+    # The waveform body is reconstructed from ALL A5 frames (data + terminator).
     # The terminator frame's contribution includes the 26-byte footer at its end.
     #
-    # Reconstruction layout (confirmed from M529LIY6.N00, 2026-04-21):
+    # Reconstruction layout (confirmed from M529LIY6 captures, 2026-04-21):
     #   all_bytes = contributions from A5[0..N] + terminator_contribution
     #   body      = all_bytes[:-26]   (everything except the last 26 bytes)
-    #   footer    = all_bytes[-26:]   (last 26 bytes = the N00 footer)
+    #   footer    = all_bytes[-26:]   (last 26 bytes = the waveform file footer)
     #
     # The footer bytes come directly from the terminator frame's inner content —
     # using them verbatim ensures timestamps match the device's recorded values.
 
-    # Separate terminator from data frames
+    # Separate terminator from data frames.
+    # Search from the FRONT for the first terminator (page_key == 0x0000).
+    # Do NOT use a5_frames[-1] — if _a5_frames contains stray frames from a
+    # subsequent event (a known get_events side-effect), the last frame will
+    # not be the terminator and the footer will be mis-identified.
+    term_idx: Optional[int] = None
+    for _i, _f in enumerate(a5_frames):
+        if _f.page_key == 0x0000:
+            term_idx = _i
+            break
+
+    if term_idx is not None:
+        body_frames = a5_frames[:term_idx]
+        term_frame  = a5_frames[term_idx]
+    else:
         body_frames = a5_frames
-    term_frame: Optional[S3Frame] = None
+        term_frame  = None
-    if a5_frames and a5_frames[-1].page_key == 0x0000:
-        body_frames = a5_frames[:-1]
-        term_frame  = a5_frames[-1]
 
     all_bytes = bytearray()
 
@@ -660,14 +671,14 @@ def write_n00(
         f.write(footer)
 
 
-def read_n00(path: Union[str, Path]) -> Event:
+def read_blastware_file(path: Union[str, Path]) -> Event:
     """
-    Parse a Blastware .N00 file into an Event object.
+    Parse a Blastware waveform file into an Event object.
 
     NOT YET IMPLEMENTED.
 
     Args:
-        path: Path to the .N00 file.
+        path: Path to the waveform file.
 
     Returns:
         Event object with waveform data populated.
@@ -675,7 +686,7 @@ def read_n00(path: Union[str, Path]) -> Event:
     Raises:
         NotImplementedError: always (pending implementation).
     """
-    raise NotImplementedError("read_n00() is not yet implemented")
+    raise NotImplementedError("read_blastware_file() is not yet implemented")
 
 
 # ── MLG file writer ───────────────────────────────────────────────────────────

minimateplus/client.py

@@ -608,7 +608,7 @@ class MiniMateClient:
                         )
                         if a5_frames:
                             a5_ok = True
-                            ev._a5_frames = a5_frames   # store for write_n00
+                            ev._a5_frames = a5_frames   # store for write_blastware_file
                             _decode_a5_metadata_into(a5_frames, ev)
                             _decode_a5_waveform(a5_frames, ev)
                             log.info(
@@ -624,7 +624,7 @@ class MiniMateClient:
                         )
                         if a5_frames:
                             a5_ok = True
-                            ev._a5_frames = a5_frames   # store for write_n00
+                            ev._a5_frames = a5_frames   # store for write_blastware_file
                             _decode_a5_metadata_into(a5_frames, ev)
                             log.debug(
                                 "get_events: 5A metadata  client=%r  operator=%r",
@@ -783,29 +783,29 @@ class MiniMateClient:
     def save_blastware_file(self, event: "Event", path: "Union[str, Path]", serial: str) -> None:
         """
         Download the full waveform for *event* and save it as a Blastware-
-        compatible .N00 / .9T0 file at *path*.
+        compatible Blastware waveform file at *path*.
 
         This is a convenience wrapper that calls download_waveform() (which
         performs the complete SUB 5A BULK_WAVEFORM_STREAM download) and then
-        calls write_n00() from blastware_file.py to encode the result.
+        calls write_blastware_file() from blastware_file.py to encode the result.
 
         Args:
             event:  Event object with waveform key populated (from get_events()).
             path:   Destination file path.  Caller should use blastware_filename()
-                    to pick the correct .N00 / .9T0 extension.
+                    to pick the correct extension via blastware_filename().
             serial: Device serial number (e.g. "BE11529") — passed to
                     blastware_filename() for reference, but the caller supplies
                     the final path.
         """
         from pathlib import Path as _Path
-        from .blastware_file import write_n00 as _write_n00
+        from .blastware_file import write_blastware_file as _write_blastware_file
 
         a5_frames = self.download_waveform(event)
         if not a5_frames:
             raise RuntimeError(
                 f"save_blastware_file: no A5 frames received for event#{event.index}"
             )
-        _write_n00(event, a5_frames, path)
+        _write_blastware_file(event, a5_frames, path)
         log.info(
             "save_blastware_file: wrote %s (%d A5 frames)",
             path, len(a5_frames),

minimateplus/framing.py

@@ -458,7 +458,7 @@ class S3Frame:
     data: bytes         # payload data section (payload[5:], checksum already stripped)
     checksum_valid: bool
     chk_byte: int = 0   # actual checksum byte received from wire (body[-1])
-                        # needed for N00 file reconstruction: when the last data byte
+                        # needed for waveform file reconstruction: when the last data byte
                         # is 0x10 and chk_byte ∈ {0x02, 0x03, 0x04}, the DLE+chk pair
                         # must be included in the DLE-strip operation to correctly
                         # reconstruct the Blastware binary body.

minimateplus/models.py

@@ -494,7 +494,7 @@ class Event:
     _waveform_key: Optional[bytes] = field(default=None, repr=False)
 
     # Raw A5 frames from the full bulk waveform download (full_waveform=True).
-    # Populated by get_events() when full_waveform=True; used by write_n00().
+    # Populated by get_events() when full_waveform=True; used by write_blastware_file().
     _a5_frames: Optional[list] = field(default=None, repr=False)
 
     def __str__(self) -> str:

minimateplus/protocol.py

@@ -545,7 +545,7 @@ class MiniMateProtocol:
 
         By default the termination frame (page_key=0x0000) is NOT included in the
         returned list.  Pass include_terminator=True to append it; the blastware_file
-        writer needs the terminator frame's body to reconstruct the N00 footer.
+        writer needs the terminator frame's body to reconstruct the waveform file footer.
 
         Args:
             key4:                4-byte waveform key from EVENT_HEADER (1E).
@@ -557,7 +557,7 @@ class MiniMateProtocol:
                                  (default 32; a typical event uses 9 large frames).
             include_terminator:  If True, append the terminator A5 frame
                                  (page_key=0x0000) to the returned list.  The
-                                 terminator carries the N00 footer bytes.
+                                 terminator carries the waveform file footer bytes.
                                  Default False preserves existing caller behaviour.
 
         Returns:

sfm/server.py

@@ -61,7 +61,7 @@ from minimateplus import MiniMateClient
 from minimateplus.protocol import ProtocolError
 from minimateplus.models import CallHomeConfig, ComplianceConfig, DeviceInfo, Event, PeakValues, ProjectInfo, Timestamp
 from minimateplus.transport import TcpTransport, DEFAULT_TCP_PORT
-from minimateplus.blastware_file import write_n00, blastware_filename
+from minimateplus.blastware_file import write_blastware_file, blastware_filename
 from sfm.cache import SFMCache, get_cache
 from sfm.database import SeismoDb
 
@@ -874,7 +874,7 @@ def device_event_blastware_file(
                         to be populated from compliance config)
 
     Performs: POLL startup → get_events(full_waveform=False, stop_after_index=index)
-    → write_n00() → FileResponse.
+    → write_blastware_file() → FileResponse.
     """
     log.info(
         "GET /device/event/%d/blastware_file  port=%s host=%s",
@@ -890,7 +890,7 @@ def device_event_blastware_file(
                 # the full bulk download.  Using full_waveform=True produces a file
                 # ~8x larger than Blastware's because it includes all post-event
                 # silence chunks.  The metadata-only a5_frames (with terminator) are
-                # sufficient for byte-perfect write_n00 output.
+                # sufficient for byte-perfect write_blastware_file output.
                 events = client.get_events(full_waveform=False, stop_after_index=index)
                 matching = [ev for ev in events if ev.index == index]
                 return matching[0] if matching else None, info
@@ -928,7 +928,7 @@ def device_event_blastware_file(
 
     # Write to /tmp so FastAPI can stream it back
     out_path = Path("/tmp") / filename
-    write_n00(ev, a5_frames, out_path)
+    write_blastware_file(ev, a5_frames, out_path)
     log.info(
         "blastware_file: wrote %s (%d A5 frames, serial=%s)",
         out_path, len(a5_frames), serial,