Both preceding sections split the file at 0x88 and called everything after it
the slot table. Wrong: this page already documents the container as GDHA + a
146-byte header + a zlib stream, and savegame.rs implements it. 0x88 is where
the Z1/zlib payload begins (5a31 = 'Z1', 78da = zlib), so the bytes I treated as
slot fields are deflate output.
Invalidated: the '6 pointer-shaped words in the slot region' are not words and
not pointers, so the false-positive rate I derived from them measured nothing.
Survives with different reasoning: 'the slot region is byte-identical' is true
because the two COMPRESSED streams are identical, which does imply identical
payloads -- and inflating both confirms it, 545 bytes byte-for-byte equal.
Stands and is better founded: all 12 differing words are in the header, which is
the only uncompressed region and therefore the only place a word-wise diff means
anything.
Done correctly, the result is a confirmation rather than a discovery: inflating
all three payloads reproduces the documented clear-ratio field stepping 5 -> 6
on the developed save.
The lesson: I found Z1/78da by inspection and nearly wrote it up as new. It was
already decoded four sections above where I was appending. Reading the whole
page first would have saved two wrong commits, and the wrongness was not
cosmetic -- a pointer census ran over deflate output and produced a
plausible-looking table.
Splitting the same comparison at the documented slot-table boundary (save+136):
the header holds 34 words and ALL 12 differing words, while the slot table holds
35 words and ZERO differences. The slot region is byte-identical between the two
same-state saves, so the documented slot fields are untouched by the churn and a
slot-region diff is meaningful where a whole-file diff is not.
Also corrects my own framing from the previous commit. The slot region contains
6 words in the pointer value range that do NOT change across runs -- a pointer
captured from a moving heap would not sit still, so those are data whose values
merely land in 0x70-0x8F / 0xB0-0xBF. The value-range test alone does not
identify a pointer; a third of what it flags here is not one. What identifies a
pointer is being pointer-shaped AND varying, ideally with a shared constant
delta. So '26% of the file is heap addresses' overstates it and the defensible
figure is the 8 header words that are both.
Left the earlier section in place with the correction after it: a value-range
classifier on 32-bit words always has a false-positive rate, and quoting its raw
count as a fact about the format is the error.
Comparing the two same-state saves (both 276 bytes), only 12 of 69 u32 words
differ, and nine of those carry guest addresses -- 0xBC/0xBD/0x70 prefixes, the
same regions the runtime work uses. Three differ by exactly 0x101080 and two by
exactly 0x300000: a shared constant offset is what a relocated heap does to a
pointer and not what data does.
The split is sharp: pointer-shaped words are 26% of the file and 44% of them
differ; non-pointer words are 8%. So a quarter of this structure is captured
heap addresses that change run to run regardless of play. That is the concrete
form of the page's existing 'much of the rest is uninitialised memory', now
demonstrated by constant deltas rather than inferred from odd-looking values.
Also records that my first pass was wrong: a byte-wise three-way diff reported
135 of 276 bytes differing, but game03 is 280 bytes with a ZERO-byte common
suffix, so offsets do not correspond past 0x00A. The valid equal-length pair
gives 30 bytes in 12 words. The inflated figure looked plausible -- half a save
changing is what dense state would do -- which is why it is written down.
Static analysis of the header builder (0x822870b4..0x82287128) shows the GDHA
container header carries a SUMMARY of the progress block, and the screens read
that: hdr+0x14 <- GHAD+52, hdr+0x18 <- GHAD+48, hdr+0x1c <- +24 (Points),
hdr+0x20 <- +4 (flight), hdr+0x24 <- the computed clear ratio, hdr+0x28 <- +12.
savegame_edit.py copies the donor header verbatim, so payload-only probes left a
stale summary — which is why +52 looked refuted.
Patching both (hdr[0x14] = 5, ghad[+52] = 5) makes the title read
"STAGE 05 - Star System Escape", load it, brief the Gallia Asteroid Group, and fly
an asteroid-field mission with a different objective and roster. So +52 is the
stage number, 1-based, and one u32 chooses the mission.
Also corrected in the GHAD table: +48 is the Game Status enum (0 = At Standby,
matching the screen's STATE_STAND_BY/STAGE_CLEAR/GAME_CLEAR list) and +12 is Times
Cleared, both via their header mirrors.
This unlocks runtime capture in containers other than Stage_S02 (the 85 XBG7
misses, box identity, ship-placement generalisation) and per-stage unit
definitions. Slot 01 was backed up and restored byte-identically.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NptfmpjdpNCKEez6d2xvA9
Four probes against slot 01 (the save the title-menu screens read), each backed up
and restored byte-identically:
- SHAB[1..7] filled -> MISSION SELECT still locks Stage02-08, cursor will not
leave Stage01. The per-stage record table is not the unlock gate; the earlier
SHAB[1] attempt used a throwaway slot and could not show this.
- GHAD +36/+52/+56 = 5 -> still locked, panel still STAGE 02 / EASY.
- GHAD +16 = 4 -> panel still STAGE 02, so it is not a 0-based stage index.
- live-RAM writes into the loaded GDHA header -> panel unchanged.
The useful part is why the panel cannot answer this: guest RAM at that screen holds
NO payload bytes (neither the 4101/4101/79 triple nor the 54-byte develop blob),
but it does hold the save's GDHA container header with a summary copy of Points,
flight time, clear ratio and a FILETIME. savegame_edit.py copies the donor header
verbatim, so a payload edit leaves that summary stale — "the panel did not change"
therefore cannot separate "not the stage field" from "the panel never reads the
payload". Future stage/difficulty probes must patch the header too, or be judged by
what the game does on load.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NptfmpjdpNCKEez6d2xvA9
build_ship_model resolves each placement with find(|m| m.name == p.resource) --
first match wins -- so a repeated resource name inside a container would draw
the wrong geometry. It cannot happen: decoding every XBG7 resource in all 22
stage containers gives 4603 resources and ZERO repeated names. Per ship it is
tighter still: e106 wants 9 distinct names and decodes exactly 9 models for 11
placements, e105 9 for 9, f105 5 for 6.
Two of the three remaining candidates for the user-reported viewer bug are now
gone (this and include_external), leaving mirror handling and the exhaust cones,
plus the untried visual comparison.
The container sweep also reconciles a number I flagged earlier: the disc has 22
stage CONTAINERS -- Stage_S01..S16 plus Stage_S24..S29 -- i.e. 16 story stages
plus 6 extra. The save screen's 16 STAGE sprites and the notes' "22 stages" are
both right and count different things; neither gets edited to match the other.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Two results, both from a safe probe.
Slot 03 was given SHAB[0] = (a=1, b=12345, c=60000) -- a one-minute best time --
and MISSION SELECT still showed 4612 P EASY / 05:24.77 EASY, i.e. slot 01's
numbers. So the title-menu screens read the AUTO-SAVE, and any probe written to
a throwaway slot is invisible there. The previous SHAB identification is
unaffected: it matched slot 01's own bytes, which is what the screen renders.
The consequence is a decision, not a task: mapping the difficulty enum (a) or
testing b needs slot 01 itself edited -- the only save with real progress. Left
undone deliberately and flagged in the doc; a full content backup exists and
slot 01's bytes are archived, so it is recoverable, but it is the user's call.
Also: High Score 4612 is stored NOWHERE. It is absent from both .gpd profile
files, all three saves (compressed and inflated) and xconfig.settings, while the
best time 324773 is present in slot 01 alone. The score is computed at display
time, which is why SHAB[0].b = 4101 does not equal it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
EXTRAS -> MISSION SELECT renders per-stage records and they match the table.
Stage 01 shows "High Score 4612 P EASY / Best Time 05:24.77 EASY" while SHAB[0]
is (2, 4101, 324773, FILETIME): 324773 ms IS 5m24.773s, the displayed best time.
Sixteen records, sixteen story stages -> the table is indexed by stage, and
record 0 is Stage 01, the only stage this save has cleared.
a = 2 difficulty of the record (both entries tagged EASY)
b = 4101 NOT the displayed high score 4612; equals GHAD +24/+28
c = 324773 best clear time in ms -- confirmed against the screen
d,e FILETIME
This also explains the probe that filled SHAB[1] and changed nothing: the table
holds stage RECORDS, not progress, and Stage 02 has never been cleared so its
record is legitimately empty. Promotes the earlier "per-stage result record"
guess to confirmed for the layout.
Route: title -> EXTRAS -> MISSION SELECT. Only cleared stages are selectable (16
d-pad presses never left Stage 01) and the screen has its own difficulty
selector (Y).
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Disassembling around the serializer names its mirror and the whole read side:
deserializer 0x822C0380 (reads GDAA + phase string), GHAD reader 0x822BF858
(called with save+8, pairs with the writer 0x822BF678), SHAB reader 0x822BFD60
(save+136, count 16).
The GHAD reader is a plain unrolled byte copy with no clamping or validation
anywhere, which is why hand-written field values survive into the object exactly
as written.
The deserializer's only caller builds its argument as
lwz r11,4(r30) / lwz r11,0(r11) / addi r4,r11,304, so the save state lives at
+304 of a game object and every field now has a fixed absolute offset there --
Points at +336, clear ratio at +320, the develop blob at +380, the SHAB table at
+440. That is what a live-RAM read of the save state needs.
Recorded as a negative too: searching those absolute offsets does NOT find the
panel's populate code. lwz rX,336(rY) has 193 matches, and the windows holding
several right offsets at once are a vtable thunk table (slots 308-340) and a
float-parameter block. The stage/difficulty fields need the screen-side path.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Static, no emulator. The LOAD/SAVE screen's config keys sit in .rdata as a
pointer array at 0x820a0074, identified as config keys (not loose strings) by
the Arsenal's own key list sitting a few hundred bytes earlier and matching its
pak record exactly.
- GAME_VERY_HARD exists alongside EASY/NORMAL/HARD, while the stage tables
only carry BonusPoint_EASY/NORMAL/HARD -- a fourth, unpriced tier.
- Game Status is a 3-valued enum: STATE_STAND_BY (our save's "At Standby"),
STATE_STAGE_CLEAR, STATE_GAME_CLEAR.
- Exactly 16 STAGE sprite keys, matching weapon.tbl's stage01..16 (plus 6
tutorials and 6 challenges). So 16 is the story-stage count and the "22
stages" figure used elsewhere counts a different set -- flagged, not
silently changed.
Also recovered: the panel's field names and positions (Points, FlightTime
%03d:%02d:%02d, ClearTimes, CompletionRate, RatioOfClear, Index, Label, Date,
BrokenData).
It does NOT name the stage/difficulty save fields, and it explains why the probe
sweep could not: the screen picks a sprite key BY INDEX through a config lookup,
so there is no lis/ori immediate to xref back to the selecting code.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Extends the previous refutation to a sweep. Probed with no effect on STAGE 02 or
Difficulty EASY: every scalar in the GHAD block (+0, +12, +16, +20, +28, +32,
+36 at 1/3/9, +40 u64, +48, +52, +56, +60, +64 raw), SHAB[0].a, and the SHAB
FILL COUNT in both directions -- record 1 filled with a copy of record 0, and
record 0 cleared. The "stage = filled-record count + 1" idea dies with it, and
so does the reading that made SHAB a per-stage result table by that route.
The panel does re-read each slot: slot 02 holds Points 4101 / Clear Ratio 5 %
and displays exactly that while its neighbours show 101 / 6 %.
Left: the phase string, the trailer, or the blob. Recorded caveat -- every save
on disc is genuinely Stage 02 EASY, so "field not found" and "panel does not vary
those two labels per slot" are not yet separated, and another probe round cannot
separate them. The next move is static: find the code that formats STAGE %02d
and read which offset it loads.
savegame_edit.py --set now packs an int into raw_* byte fields.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Those three fields all hold 2, and "difficulty or stage, undecidable from one
save" has been the reading since the format was parsed. Writing saves makes it
decidable and the answer is neither.
boot_menu.sh boots to the title menu WITHOUT loading anything, and LOAD GAME's
slot list renders each slot's Details panel from that slot's payload. Extra
slots can be fabricated (copy the directory plus a gameNN.header with its
UTF-16BE display string and ASCII name patched), so four probes fit in one boot,
read-only.
Probed: +36 at 1/3/9, +52 and +56 at 1/9, and +0, +16, +32, +48, +28,
SHAB[0].a. Every one left the panel at STAGE 02 / EASY / At Standby /
Times Cleared 0.
The negative is meaningful because the panel does read each payload -- slot 02
shows 5% clear ratio against the others' 6%, and Points tracked +24 exactly.
Two controls: patching a slot header to "STAGE09 HARD" changed nothing (the
display is payload-driven, not header text), and the row date follows the
container FILETIME.
Remaining candidates: +12, +20, +40 (u64), +60, +64, or the phase string.
Also here: savegame_edit.py --slot for SHAB records, and boot_menu.sh itself --
nav_probe.sh's boot loads a save, which with probe slots on disc loads a probe,
and a dropped d-pad step there put A on TAKE OFF and spent a boot loading a
mission.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Three hand-written probe saves settled what a mission payout could not.
all 54 owned -> every tab fills and the lists WRAP, giving exact counts
(GUN 8, BEAM 8, LASER 4, MPM 5, ASM 5, B/R 7, CANNON 6,
SPECIAL 6 = 43 displayed) and confirming the display order is
weapon.tbl's order item-for-item. It also killed the idea
that gate-unmet owned flags are suppressed: Maelstrom Bomb
(Stage 6) and Grav Cannon XGS (Stage 12) both rendered at a
Stage-2 save.
only 9 + 39 -> STILETTO BG1 Developed (control) AND TOMAHAWK ALPHA RAIL GUN
Developed. The CANNON block starts at 39, not 38.
only 39 + 48 -> JAMMING SYSTEM Developed. SPECIAL starts at 48, and with six
SPECIAL items the array closes exactly at 53, nothing spare.
So the blob is indexed by strings.tbl's item order -- the display order PLUS the
items only the localisation file carries (Adhesive Mine B2A, and three of
Ballista GSH / Designator LH / Smoke Marker Launcher / Bumble UV). They never
appear in the Arsenal but they hold slots, which is the entire reason the tail
looked broken. It also explains the retail save's five "unexplained" owned
entries at 33 and 45/46/47: cut items, shipped flagged owned, never rendered.
That weapon.tbl's No_Equipment..Wep_83 run is ALSO 54 long is a coincidence, and
it cost real time -- the two orders agree only to index 32. Recorded as such.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The container's derived fields turned out to be reproducible -- length+10 at
+0x30, payload length at +0x8c, adler32(payload) at +0x8e, everything else
copied -- and savegame_edit.py re-wraps a real save BYTE-IDENTICALLY, which is
the check that those three are the only ones. A hand-written save then loaded.
That replaced a blocked experiment (the tail question needed a mission payout,
and none of the currently developable items even sit in the disputed range) with
a direct one: write the blob, read the Arsenal.
- controls: 4 at index 9 -> STILETTO BG1 Developed, 21 -> FALCON 9AM
Developed. A hand-written 4 reaches the screen.
- tail: 4 at 33 and 45 left their rows dashed (both on screen, not below the
fold), and 38 left TOMAHAWK ALPHA RAIL GUN at "0 P" -- not owned. So the
tail is not the weapon.tbl order continued.
- clearing the real save's {22,26,39,46,47} cost the Tomahawk its Developed
status, which puts its flag in that set (39 positionally) -- but a uniform
+1 fails for SPECIAL, so no shift is asserted. Indices >=32 stay marked.
Two behaviours fell out. The title RE-DERIVES developable state on load and
announces it ("You can now develop Broad Sword ..."), so only the 4s are stored
state and a written 2 is pointless. And a no-cost item is bought for 0 P rather
than granted -- TOMAHAWK at "0 P" is what unowned looks like -- which is the
actual reason items read Developed in a save where nothing was spent.
Slot 03 was restored from its archived original (md5 verified); slots 01/02 were
never touched.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
GP_HANGAR_ARSENAL.pak's screen config points at weapon.tbl (item ids, in the
8-category display order) and strings.tbl (names, descriptions, and a
"Conditions to obtain" block per item). The id run No_Equipment .. Wep_83 is
exactly 54 long -- the save blob's length -- and all 60 conditions blocks are
extracted to a CSV: gates are stage completion, a predecessor item, or an ace
kill; costs run 3000-350000 P, and 20 items cost nothing once gated (which is
why items the player never bought read as Developed).
Predicting the save state from those conditions -- before looking at the blob --
says exactly six items are developable here, and the blob's six 2s sit on those
six, in weapon.tbl order, at indices 1/5/10/12/27/31. With the four obtained
items and the differential's own two transitions that is twelve concordances
over indices 0-31, nothing fitted. Broad Sword SG1 at index 5 needed scrolling
the GUN list to see, which is the only one the first screenshots missed.
The tail is NOT settled and is marked so: the Tomahawk is weapon.tbl index 38
and the screen shows it Developed, but blob[38] = 0, and the other tail 4s
(33/39/45/46/47) land on items the Arsenal shows as locked -- the SPECIAL tab is
entirely empty. A +1 shift does not repair it either. Settling it needs a second
development in a late category, which needs a mission payout.
Also recorded: IDXD string pools dedupe repeated values, so only the first
record of a table can be read from the token stream -- record 2 shows just its
unique values, record 6 no cost at all.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
A third save, taken in the running game after developing exactly one item
(Light Machine Gun MG I, 4000 P) and declining the mount prompt, moves exactly
three things against the same-state save:
+24 Points 4101 -> 101 and +28 does NOT move, which separates the
pair one save could not tell apart; the
Details panel then reads Points 101 P, so
+24 is the spendable balance
+8 clear ratio 5 -> 6 so the ratio counts collection, not stages
+68 blob[1],[2] 2->4, 0->2 the item bought, and the successor the game
announced as newly developable
One action, two blob transitions, two on-screen events in the same order — which
is what makes 0 locked / 2 developable / 4 developed a reading rather than a
guess, and rules out a plain owned-bitmask (it could not hold the middle state).
Which item each of the 54 indices is stays open: the arsenal id lists in
GP_HANGAR_ARSENAL.pak union to 35, and MG I sits at index 1, not 0.
Also recorded: inside a modal yes/no dialog a 60 ms d-pad tap is ignored (the
list menus accept it), and the develop confirm starts on NO while the mount
prompt right after it starts on YES.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Made a second save in-game (READY ROOM -> SYSTEM -> SAVE GAME -> empty slot) so
the format had a differential to read against. nav_probe.sh drives it: boot to
the READY ROOM, walk a scripted step list, screenshot after every step and stamp
every save file's md5, so the trail says which keypress wrote a save. That stamp
is what caught the first attempt failing -- the save confirm starts on YES,
unlike the load confirm which starts on NO, so the load flow's extra up-press
selected NO and wrote nothing.
Result 1: saving the same loaded state into a new slot produces a BYTE-IDENTICAL
545-byte payload. Only the GDHA header moves, and every byte that moves is either
the container FILETIME or one of the guest-pointer words -- which empirically
confirms those words are uninitialised padding rather than data. So the payload
holds no timestamp, no slot number and no name; a save's identity is entirely in
its content header.
Result 2: the LOAD/SAVE screen's Details panel prints Points 4101 P, Flight Time
000:05:24 and Clear Ratio 5 % for exactly this state, which names GHAD +24
(Points), +4 (flight time in ms -- 324773 ms = 5m24.773s) and +8 (clear ratio %).
Difficulty EASY and STAGE 02 both being 2, and three fields holding 2, is left
undecided on purpose: one save cannot separate them.
Result 3: the 16 SHAB records are not the UI's save slots. The UI has 20, slots
are separate gameNN files, and record 0's FILETIME stayed at 2026-07-23 in a save
written on 2026-08-11 -- so the table is part of the game state, most likely a
per-stage result record (one stage finished, one record filled), which the next
cleared stage will falsify or confirm.
The original save was backed up first and is untouched; the new save went to an
empty slot.
The whole retail save is 545 bytes: a GDHA container wrapping a zlib payload,
which is a chunk stream — 'GDAA', a length-prefixed game-phase name (GP_BUNK,
one of the title's GP_* screen ids), a 'GHAD' 122-byte progress block, a
count-prefixed table of 16 20-byte save slots, and a trailer.
None of it is guessed. The layout comes from the serializer at 0x822C00E8 and
its callee 0x822BF678: the writer primitive is 0x821885A8(stream, buf, len), the
slot count 16 and the 20-byte stride are literals, and the GHAD block is ten u32,
a u64, four u32, a raw 4-byte field and a raw 54-byte blob = 122 bytes, which is
exactly what the file carries. savegame.py re-serializes the parse and asserts
byte-identity.
Because the struct is written field-by-field with no packing changes, a payload
offset is also the offset in the live save object -- save+8 for GHAD, save+136
for the slot table, and 136+16*20 = 456 is the serializer's very next access.
Confirmed independently: slot 0's trailing two u32 decode as a FILETIME to
2026-07-23 20:07:23 UTC, and the content header's display string (written by the
game) says 07/23/2026 21:08 at UTC+1; the 15 empty slots hold 2006-01-01 rather
than zero.
Field meanings are left ❔ on purpose -- the naming oracle is a diff of two
saves, and all four copies on disk are byte-identical, so a second save has to
be made first. Nothing has been written back to any save.
