Ultima IV: Quest of the Avatar (GOG)

Source and fixture boundary

The local fixture comes from the Internet Archive gog_collection item pinned in test/candidate-corpus/manifest.json. Its RAR is 12,548,654 bytes with SHA-1 a75b5a57226650c47fe8f8cdb0872c8289da1cf7; the contained GOG offline installer is setup_ultima_iv_-_quest_of_the_avatar_1.0_cs_(28045).exe, 12,548,400 bytes. GOG listed Ultima IV for USD 0.00 when this corpus was verified, but the package remains proprietary and gitignored. Nothing here grants redistribution rights for the installer or extracted game.

Reproducible installed payload (2026-10-14)

node tools/fetch-candidate-corpus.js --id=gog-free-ultima-iv --force now recovers both the pinned original installer and its installed/ tree through the existing staged publication path. Requires innoextract (validated with 1.9). The package language is en-US, not english: the latter extracts unconditional support files but silently omits the game payload. The recipe selects en-US and excludes installer temporary files.

test/candidate-corpus/gog-free-ultima-iv-files.json pins all 175 extracted files. Run node test/test-ultima4-recovery.js against pristine recovered output. A fresh recipe fetch was compared with an independent extraction and the restored fixture; every file matched byte-for-byte. This includes DOSBOX, configuration, and the four original __support/save/ templates used by the ToyVM mapping. No generated character/save state or new gameplay qualification is included. The existing runtime entry and original-file mapping remain unchanged.

Evidence and an original installer copy are retained under scratch/runs/20261014-ultima4-recovery/. As with other forced recoveries, preserve local saves separately before using --force.

Direct installer path

The original PE32 Inno wrapper was executed directly in Wine-Assembly, without host Wine. It extracted a 1,343,072-byte child and called CreateProcessW with this exact handoff:

/SL5="$10001,11966063,192512,C:\setup_ultima_iv_-_quest_of_the_avatar_1.0_cs_(28045).exe"

Wine-Assembly intentionally does not implement a general child-process model, so the wrapper reports that it cannot execute the temporary file and waits in its error dialog. A debugger dump of the live UTF-16 CreateProcessW command line supplied the handoff above. Running the extracted child directly with the original installer mounted at the named C: path reaches the native Inno language-selection UI and remains responsive; a bounded run completed 5,000 batches and 47,180 Win32 API calls there.

After proving the original and child paths, the existing local innoextract build extracted the payload for runtime acceptance. This is a local throughput and process-boundary workaround, not host Wine. The ignored extracted tree is about 17 MiB.

Bundled DOSBox runtime

The package contains the 32-bit Windows DOSBOX/DOSBox.exe, version 0.74-2.1. test/configs/ultima4-wine-assembly.conf selects core=dynamic, mounts the extracted root as C:, and launches the package's ULTIMA.COM. The launcher then transfers control to TITLE.EXE, matching GOG's own single-game config. The 3,000-cycle setting is deliberate: 50,000 nested cycles greatly increases outer interpreter work. The acceptance runs guest work continuously for a bounded 30 wall-clock seconds and captures the final frame, avoiding a machine-load-dependent assumption that a particular batch number represents a particular amount of DOS time.

The bounded acceptance runs that unchanged Windows DOSBox inside Wine-Assembly, observes both Program: ULTIMA and Program: TITLE, and captures the 320x200 title/map intro. The accepted content has at least ten colors, over 40,000 black pixels, and over 1,000 cyan pixels; the earlier orange DOSBox splash cannot satisfy that signature.

node test/test-ultima4-dosbox.js

2026-10-05 ordinary browser character creation (not gameplay)

Session87748 used source94d18605/module2e2fd8d1, the original installed DOSBox0.74-2.1 and existing dynamic-core/fixed3000/sound-disabled config. The sole local registration overlay was explicitly pinned;258production sources and280asset URLs were checked. Normal input reached main menu, I/new name Avatar, male choice, the introduction and virtue questions. The first A choice advanced the abacus; second preamble (Valor/Spirituality) was visible. No player world or movement was reached.

The300sec wall guard ended18:04:02.733Z with browser/server closed, errors[], sessionexit2. It includes operator image-review time; no compatibility fault or timing performance is inferred. Later submitted inputs after terminal were not executed. Immutable evidence: scratch/runs/20261005-ultima4-character-creation/result.json and validation.json; screenshot question2.png is character creation, not gameplay.

Next: fresh600sec ordinary route, reuse the now-observed introduction advance sequence with periodic captures, stop at actual virtue prompts and answer seven visible choices. Personal review of active world and before/after arrow movement remain mandatory. No automatic retry or synthetic save/protocol.

2026-10-05 seven choices complete, post-creation save-open failure

Continuation session59296 on the same94d18605/2e2fd8d1 completed ordinary name/sex/intro and seven personally reviewed A/B choices (A,A,A,B,A,B,A). The final narrative was advanced normally. Actual DOSBox program labels then changed TITLE→ULTIMA→AVATAR→ULTIMA→DOSBOX, and the rendered text reads Opening PARTY.SAV immediately followed by the DOS C:\> prompt. Stable after-save.png confirms no active world. No gameplay/FPS accepted.

Stopped at the concrete boundary, before the600sec guard: clean exit0/browser+serverclosed18:31:41.282Z/errors[]. Immutable result/screenshots/logs/hashes: scratch/runs/20261005-ultima4-post-creation-save-exit.

Source-only distinction: original installed PARTY.NEW exists (502bytes); PARTY.SAV is not a packaged asset and is expected to be created during play, so it must not be added as a fake fixture. Bundled DOSBox source drive_local.cpp uses fopen("wb+") in FileCreate, rb/rb+ in FileOpen and fwrite for writes; rename delegates CRT rename. Current pinned CRT maps wb+ to CREATE_ALWAYS and tracks FILE ownership. These static paths do not establish which call failed here. Next bounded passive observation should preserve actual VFS create/write/move/delete/close return values for PARTY.NEW/PARTY.SAV/MONSTERS.SAV and a small final metadata inventory; no guest writes or invented saves.

2026-10-05 correction: packaged saves and omitted GOG overlay

The preceding statement that PARTY.SAV is not packaged was incorrect. Original installed __support/save/PARTY.SAV exists (502 bytes), alongside DNGMAP.SAV (512), MONSTERS.SAV (256), OUTMONST.SAV (256). These original bytes must be retained, not replaced by an invented character save. GOG's original __support/app/dosboxULTIMA4_single.conf mounts its base then mount C "..\cloud_saves" -t overlay; its installer script creates the cloud_saves support-data folder. The inherited Wine Assembly config mounted only the base.

Session13406 completed seven reviewed choices and returned to the same Opening PARTY.SAV DOS prompt. Existing production fs trace (8 selected records,0 target drops) reads c:\party.new502 bytes, then FindFirstFile/OpenExisting read of c:\PARTY.SAV fails. Passive metadata before/after AVATAR retains all four original templates under __support/save but no root save or cloud_saves mapping. This establishes an omitted packaging setup/overlay, not a CRT repair. No guest memory writes or private Worker hooks.258 source/280 asset pins; source94d18605/module2e2fd8d1. Clean exit0 at18:54:30.420Z, browser/server closed,errors[],deadlinefalse.

Immutable trace, screenshot, cleanup and hashes: scratch/runs/20261005-ultima4-original-save-overlay-missing. No gameplay/FPS. Next: reproduce original overlay with exact template bytes and preserve persisted user saves; test setup idempotence/conflicts, then a fresh ordinary world/movement route.

The scoped packaging repair maps those four original template URLs a second time into c:\cloud_saves, restores the original DOSBox -t overlay mount after the base mount, and opts that directory into existing browser save persistence. Persistence attaches after file mounting and restores actual user bytes before execution, without a reset token. This is original-package setup, not a generated character/save bypass or engine change. Source-only tests verify byte identity, idempotence, pinned legacy-metadata backups, conflict-before-write, and actual VirtualFS persistence replacing template bytes with saved user bytes. Original host save files are untouched. The script recognizes only the exact old generated config/manifest hashes for migration; arbitrary conflicting metadata fails.

Recipe: node tools/prepare-ultima4-gog-assets.js; focused test: node test/test-ultima4-gog-assets.js. All 277 original files verify, four overlay aliases yield 282 manifest records. Browser readiness: scratch/new-games-pipeline-20261005/ultima4/SAVE-OVERLAY-READY.md, same production module2e2fd8d1, no observer. No new gameplay acceptance until a fresh ordinary world and movement route succeeds.

2026-10-05 original-overlay ordinary overworld movement accepted

Session75639 used unchanged production94d18605/module2e2fd8d1 with packaging0ef64ef7 (mainf2cce214), no observer. Fresh ordinary name/sex/intro and seven personally reviewed choices A,A,A,A,B,A,A reached AVATAR overworld. ArrowRight150ms shifted lake/castle left and logged East; ArrowLeft150ms restored terrain and logged West; idle1200ms retained position. Root personally reviewed world/east/west/idle. Narrow gameplay movement accepted, not audio/FPS/full campaign or runtime-reload persistence. Browser/server closed19:11:28.013Z/errors[]/deadlinefalse; process clear.

Original bundled DOSBox source drive_overlay.cpp shows FileOpen tries overlaydir+name (314–368), FileCreate uses create_file_in_overlay(name,wb+) (384–409), and first writes to base files switch into an overlay copy (129–146,157–176). Thus DOS C:\PARTY.SAV writes target host/VFS C:\cloud_saves\PARTY.SAV with this original mount. This is source-backed routing; no live save-file/byte capture was added to the ordinary qualification.

Immutable result, build/actual served identity, inputs, images and hash closure: scratch/runs/20261005-ultima4-overworld-movement. Earlier diagnostic now preserves original result/validation before adding explicit build metadata; both generations retained.