FM Towns cross-game recovery coverage

Session 2026-08-11 comprehensive tally of Firestaff’s byte-verified FM Towns real-data recovery across DM1, CSB, and DM2.

Latest verification (2026-08-11): the complete checkout builds successfully; the authentic CSB FM Towns handoff suite passes 6/6 executed tests (one explicitly skipped switch-only gate), and the authentic DM2 FM Towns M12, title, and NEW GAME/gameplay suite passes 3/3. These are opt-in tests and read the user-owned archives in place.

The CSB direct loose-tree handoff now carries the selected language through M11: FIRESTAFF_CSB_FMTOWNS_GAME_LANGUAGE=en binds CDATA/CHTWE.EXP, while ja binds CJDATA/CHTWJ.EXP. A shared extraction can no longer silently boot the first directory found by the filesystem scan; each selected graphics and dungeon pair must match its authentic FM Towns hashes.

Packed-media runtime coverage is now closed for CSB as well as DM2. CSB can start M11 directly from the authentic ZIP: the original IMG member and the selected GRAPHICS.DAT, DUNGEON.DAT, CHTWE/CHTWJ.EXP, MINI.DAT, and TITLE.ANM members stay in bounded RAM. Firestaff creates no loose runtime tree and does not rewrite the source archive. The real-data gates csb_v1_fmtowns_archive_launch_real and csb_v1_fmtowns_packed_m11_real cover this path.

DM1 packed media is archive-owned: M11 reads its original CUE and BIN members in bounded memory for mixed-sector CDDA dispatch and creates no FMTOWNS.BIN runtime cache. CSB’s packed route follows the same no-extraction contract.

The CSB switch-only gate was also run directly against the materialized SWITCHTW.EXP on 2026-08-10: 18/18 assertions passed. The skip above is only the default CTest invocation without the optional switch-path environment variable; it does not indicate a parser failure.

Discs used

Full per-file hashes in docs/fmtowns/all_games_real_data_hashes.json.

Cross-game byte-identical payloads

Data structures that appear byte-identical across two or three games at per-game virtual addresses:

Per-game unique payloads

Data specific to each game that other games do NOT share:

• DM1 EDM.EXP SYM1 table (1174 entries) — unique to DM1.
• CSB TMENU.EXP SYM1 table (1724 entries) — unique to CSB launcher.
• DM1 region registry (23 blocks / 994 records) — unique DM1 menu layout.
• DM1 LEVEL_SONGS — DM1-specific CDDA mapping.
• DM1 DOOR_PAL, DM_MUSIC — DM1-specific chrome.
• DM1 tmenu_input schema (TMENU.EXP event queue) — DM1 launcher.
• CSB CHTWJ.EXP, SWITCHTW.EXP, ANIMTW.EXP, UTILE.EXP — CSB-specific binaries with independent code but no SYM1 stripped from release.
• DM2 SKULL.EXP — DM2 game code, no SYM1, no shared menu-render data (different action-label set).
• DM2 GRAPHICS.DAT format (extended v4 raw-size table with an ENT1 directory in raw item 0) — DM2’s own container variant.

Shipping Firestaff modules

Every module below is source-locked with a real-data round-trip test:

Byte-verified constants + accessors

• dm1_v1_fmtowns_text_geometry (CHAR/ICON macros — same for all games)
• dm1_v1_fmtowns_icon_geometry (ICON constants — same for all games)
• dm1_v1_fmtowns_icon_category (LOAD_ICON threshold table)
• dm1_v1_fmtowns_oicon_descriptor (1344-byte OICON records)
• dm1_v1_fmtowns_dyna_buttons (English action label pool)
• dm1_v1_fmtowns_font_asset (asset 557 identity)
• dm1_v1_fmtowns_font_rasteriser (6x128 raster decoder)
• dm1_v1_fmtowns_menu_regions (23-block region registry)
• dm1_v1_fmtowns_menu_bss (12 vaddrs + PLAYER schema)
• dm1_v1_fmtowns_egb_rect (region-tree walker)
• dm1_v1_fmtowns_menu_render (end-to-end composer)
• dm1_v1_fmtowns_music_tables (LEVEL_SONGS, SPELL_COSTS, etc.)
• dm1_v1_fmtowns_edm_sym1 (1174 named symbols)
• dm1_v1_fmtowns_snd_api (36 SND_* function vaddrs)
• dm1_v1_fmtowns_tmenu_input (TMENU event schema)
• dm1_v1_fmtowns_tbios_id (8 TBIOS version fingerprints)
• dm1_v1_fmtowns_pharlap_bridge (4-slot layout)
• dm1_v1_fmtowns_direct_io (5 direct I/O ports)

Cross-game aliases

• csb_v1_fmtowns_oicon_descriptor (aliases DM1’s OICON via vaddr)
• csb_v1_fmtowns_dyna_buttons (aliases DM1’s label pool via vaddr)
• csb_v1_fmtowns_tmenu_sym1 (1724 CSB-specific launcher symbols)

Shared cross-game infrastructure

• fmtowns_pharlap_all_games (11 binary profiles, 8-game direct I/O)
• fmtowns_graphics_dat_format (legacy/ext_v1/ext_v4 classifier)
• fmtowns_geometry_all_games (per-game CHAR/ICON vaddrs)
• fmtowns_shared_tables_all_games (SPELL/PLAYER/ICON per-game vaddrs)
• fmtowns_font_raster_all_games (per-game font raster locations)
• dm2_v1_fmtowns_graphics_dat_ext_walker (source-verified ext-v4/v5 raw table and ENT1 directory traversal)

Documentation + evidence

• docs/fmtowns/all_games_real_data_hashes.json
• docs/fmtowns/pharlap_call_sites.json (502 call sites, 11 binaries)
• docs/fmtowns/TOWNSOS_BIOS_INTEGRATION.md (Tsugaru + FMT_F20.ROM system ROM and FMT_FNT.ROM glyph device)
• docs/fmtowns/CROSS_GAME_INVENTORY.md (earlier inventory)
• docs/dm1/fmtowns_real_data_hashes.json (DM1-specific hashes)
• parity-evidence/dm1_fmtowns_region_table_full.md (994 records)

Completeness

• DM1 FM Towns: 100% of extractable byte-verified real data now shipped. Every runtime table, symbol, and I/O surface a hosted-BIOS integration would need is source-locked.
• CSB FM Towns: The authenticated CHTWE/CHTWJ, SWITCHTW, MINI.DAT, portrait, dungeon-tail, utility, and source HUD routes are wired. The real English and Japanese MINI.DAT files resume through M11 into the saved map-4 state without replaying the title. C06 SAVE CHAMPIONS opens the source GAME / PORTRAIT / CANCEL dialog; its selected-portrait route preserves an authenticated CMP header and writes to the separate .firestaff/portraits medium (or INSTALLDIR\\portraits on Windows), not the read-only CD PORTRAIT catalogue. F7002_ReadCMP also imports a revalidated selected catalogue entry into the selected party slot, copying only its source name/title and planar payload. The catalog-bound selector preserves the authenticated source order, provides bounded previous/next movement, and delegates the selected row to that same import transaction. Its C06 F7083/F7084 source-coordinate file-list state, nine-row raster, bounded scroll commands, and real PORTRAIT catalogue binding are now implemented. The remaining F31E utility gap is Make New Adventure’s F7086/F7090/F7020 transaction; F31J remains closed after its separately captured first chooser. The direct F31 path can read/update an explicitly selected F0435-admitted CSBGAME.DAT, and can make its first canonical slot from the hash-verified MINI.DAT bootstrap with CEDTINC8 F7052’s 16 part keys plus F7062’s 127 header words. C06’s F31E GAME choice admits only the selected native source medium; it does not use the CD bootstrap as a save disk. The external English fmtowns-save-corpus/CSBGAME.DAT remains fail-closed, while the language-matched CSBGAME-JP.DAT is a real, F0435-admitted F31J regression corpus (SHA-256 1c3b9d8c…cf0c2a1), not a synthetic substitute.
• DM2 FM Towns: The authentic HME-242 CD path, TWANIM/TITLE/SWOOSH/END, M12 handoff, English companion overlay, title input, NEW GAME, active gameplay movement, viewport frame, native HUD plan, all 16 authentic CHAMPIONS portrait types, and the eight source action-hand selection events (116..123) are verified by the real-media M11/M12 regressions. The click owner reads the authentic 640x400 FM-Towns RAW4 rectangles and converts pointer input to Firestaff’s 320x200 presentation surface. The three source action-panel command events now reach the CMDSTR-backed runtime owner; unsupported or unavailable item/action records still fail closed. The boot receipt also retains the complete authenticated 264-record SKULL.EXP MOUSE_INPUT span (1584 bytes, FNV-1a 0x1500c4c9) and exposes raw event/flag/rect/mask candidates by source ordinal. This is evidence for context-specific UI owners, not a global hit-test: Towns reuses rectangle IDs across branches. The first context-bound consumer now identifies route ordinal 117 as the source hand_panel.action_1 branch, while event 0x70/112 closes that panel through M11. Other candidate branches remain unavailable until their live UI state owners are bound. The native inventory census resolves 129/166 source contexts; ordinals 47-49, 52-83, 99, and 110 have no matching Towns RAW4 geometry and remain fail-closed. After authenticated GAME_LOAD, the source inventory bridge can now swap a real c_hero::item[30] link with LeaderPossession, with record-pool validation, OBJECT_NULL handling, read-back verification, and rollback. M11 also consumes the real INTERFACE_CHARSHEET/0/dtImage/1 frame through the global 255-colour PAL_IRGB route and its authenticated RECT_1EE RAW4 source crop. Authenticated Towns inventory contexts route pointer input to M11 for panel and slot selection; the seven source-explicit equipment slots now commit clicks through the same authenticated exchange. The native inventory.eye record (event 71, rect 0x8222) is identified in the source champion/status context, but the current loose Towns corpus has no authenticated RAW4 rectangle for it; M11 therefore keeps the click fail-closed until that geometry is recovered. This is not a claim of complete inventory parity: source text, the unproven non-equipment owners, and rune/moneybox/status mutations remain unavailable and fail closed. The native viewport event 0x50/rect 0x0007 reaches the DM2 c_rwbb target resolver and cannot fall through to DM1’s C080 handler. Inventory/dialogue pointer ownership and map-dependent viewport mutations remain fail-closed gates until their source owners are bound. Direct launch also accepts the authenticated loose fmtowns_iso tree. Native startup works from the exact loose TWANIM/SKULL/TITLE/SWOOSH/END members even without a ZIP; when the original HME-242 ZIP is beside that tree, it remains the CDDA owner. The corpus contains no FM Towns SKSAVE artifact, so save/resume remains fail-closed; DOS SKSAVE files are not used as a Towns substitute.

What is intentionally NOT shipped

• Full extended-format GRAPHICS.DAT coverage for CSB (0x8001) and DM2 (0x8004). The DM2 raw table, ENT1 directory, and authenticated FM Towns IMG2/U4 hand-action decode are shipped; broader per-record presentation coverage remains game-specific work.
• TownsOS BIOS runtime execution. Requires Tsugaru integration or hosted TBIOS shim (see integration doc).
• JDM Shift-JIS glyph bitmaps. Byte-verified 2026-08-07: the Japanese Rev 1 disc contains NO game-owned Shift-JIS bitmap. JDATA/GRAPHICS.DAT asset 557 (768 bytes) is byte-identical to the English DATA/GRAPHICS.DAT asset 557 — the Japanese release reuses the same ASCII font raster for Latin characters and delegates all kanji glyphs to TownsOS TBIOS at runtime. See dm1_v1_fmtowns_jdm_font.{h,c} for the source-locked resolution contract: ASCII via the shared rasteriser, Shift-JIS pairs via a caller-supplied TBIOS callback (fail-closed if none).
• Atari ST and Amiga variants. Out of scope per user directive.