For pure DOS executables, the e_lfanew field at MZ header offset 0x3C
is uninitialized garbage. Duke Nukem 2's EXE had bytes that form a
negative int32 (-1878619136), which was used as an array index causing
ArrayIndexOutOfBoundsException.
Now checks peOffset < 0 and returns 'dos' (no Windows signature found).
Many classic DOS games (Blood, DOOM, Duke Nukem 3D, Quake) use
DOS/4GW or DOS/32A — 32-bit DOS extenders with Linear Executable
(LE) format. My code was detecting LE as 'windows', causing these
games to be incorrectly flagged as unplayable.
Only PE (Portable Executable / Win32) and NE (New Executable /
Windows 3.x) are actually Windows.
Previously when no IGDB matches were found, the button next to the
search box changed from 'Search' to 'Upload' after the first search.
Since the text is editable and users may want to refine their query,
this button should always trigger a search.
Upload is still available via:
- The 'Upload anyway as "..."' button (shown after failed search)
- The 'Use filename: ...' button at the bottom
- Move platform detection before setup bundle creation
- Only create setup bundle when platform != 'windows'
- Also hide the Setup button in GameDetail for Windows games
- Windows setup executables (INSTALL.EXE) can't run in DOSBox anyway
js-dos v8's C extraction code (jsdos-libzip.c) iterates ZIP entries
linearly and calls mkdir() on each directory entry. If a child
directory appears before its parent, mkdir() fails with perror()
and exit(1) — fatal crash with 'No such file or directory'.
Previous approach wrote directory entries interleaved with files,
deepest-first (from the file path right-to-left). Now:
Phase 1: Walk entire file tree to discover ALL directories
Phase 2: Write ALL dir entries sorted (shallowest first via TreeSet
natural ordering — '/' sorts before any letter)
Phase 3: Write .jsdos/ config files
Phase 4: Write game files (parents already exist from Phase 2)
This guarantees that mkdir("NAS50TH/TRACKS/") runs before
mkdir("NAS50TH/TRACKS/WILKES/"), which runs before open().
Many DOS game ZIPs include CloneCD backups (.ccd/.img/.sub) or
other disk images that are not needed for gameplay — the game data
is already extracted in the working directory. These can be 300MB+
and cause WASM memory exhaustion in js-dos.
Added a SKIP_EXT set that filters out known disk image extensions
during game file pass. The .jsdos config pass is unaffected.
js-dos reads ZIP entries sequentially and needs .jsdos/dosbox.conf and
.jsdos/jsdos.json first to configure DOSBox. Java's Files.walk() uses
filesystem readdir order which put them at the very end of the ZIP
(after the 328MB CloneCD image), causing extraction failures.
Now:
1. First pass: walk .jsdos/ directory and write config files first
2. Second pass: walk everything else (excluding .jsdos/) in sorted order
3. All directory ancestors are still added as explicit entries
4. .sorted() ensures deterministic, alphabetical entry order
Previously only the immediate parent directory was added as a ZIP
entry. For deeply nested paths like NAS50TH/TRACKS/WILKES/WILKES.DAT,
only NAS50TH/TRACKS/WILKES/ was created — but NAS50TH/TRACKS/ and
NAS50TH/ were skipped (they're only parents of other directories,
never the immediate parent of a file).
Emscripten's FS.createDirectory() fails if parent doesn't exist,
so intermediate directories must be in the ZIP too.
Now walks up the full ancestor chain with a while loop.
js-dos uses Emscripten's virtual filesystem which requires explicit
ZIP directory entries (names ending with '/') to create directories.
Java's ZipOutputStream only writes file entries, so subdirectories
like NAS50TH/TRACKS/WILKES/ were never created — causing Emscripten
'No such file or directory' errors for any path inside them.
- createBundle: before writing each file entry, add its parent
directory as an explicit ZIP entry if not already added
- Affects all games with subdirectory structures (NASCAR Racing 2,
Gus Goes to Cyberopolis, etc.)
- Use a HashSet to track already-added directories (no duplicates)
- Game.java: add 'platform' field ('dos'/'windows') + 'isPlayable' helper
- UploadResource.java: detect EXE type by reading PE/NE header during upload
- GameResource.java: allow PATCH to update platform
- GameCard.svelte: show 🪟 Win badge for Windows games (blue style)
- GameDetail.svelte: show platform badge, disable Play for Windows with
'Unplayable' button; add platform dropdown to edit form
- Play.svelte: show blocking overlay for Windows games with 'Try anyway'
option for users who want to attempt it
- Fix flattenSingleDir: flatten when exactly 1 root directory exists,
even if other metadata files (file_id.diz, *.nfo) are present at root
- Fix buildDosboxConf/buildJsdosJson: add 'cd <dir>' before executable
when it lives in a subdirectory, since DOS treats '/' as switch char
(previously 'mastori2/ORION2.EXE' was parsed as command 'mastori2'
with switch '/ORION2.EXE')
- Remove SockdriveResource.java entirely
- Remove bundleType field from Game.java (was 'standard'/'sockdrive')
- Simplify GameResource.java download endpoint
- Clean up upload resource
js-dos v8's window.Dos(container, { url }) expects the URL to point
to a .jsdos ZIP archive, not a loose dosbox.conf file. The
'sockdrive' mode was serving game files loosely with a URL pointing
to a raw config file, causing: 'Unable to add .jsdos/jsdos.json
into bundle.zip'.
Changes:
- Removed SOCKDRIVE_THRESHOLD_MB and the entire sockdrive branch
- Always create a .jsdos ZIP bundle via createBundle()
- Optimized createBundle: no temp dir copy (saves 2x I/O for large
games), uses STORE compression (level 0) since DOS files are
often already compressed
- Removed dirSizeMB(), copyDir() and setup config builders —
no longer needed after removing sockdrive mode
- frontend bundleUrl()/setupBundleUrl() always use the standard
/games/{id}.jsdos path
- GameService.delete cleanup simplified
The previous 200M limit on quarkus.http.limits.max-body-size and
multipart input-part.max-size rejected games over 200MB. DOS CD-ROM
games can easily exceed this (e.g. DOOM 95 full CD, Diablo). Raised
to 2048M to cover the largest DOS/CD-ROM game archives.
When a game archive contains SETUP.EXE, INSTALL.EXE, CONFIG.EXE or
CUSTOM.EXE (or .com/.bat variants), the upload now:
- Detects and stores the path in game metadata (setup_exe / has_setup)
- Generates a second .jsdos bundle with SETUP.EXE as autoexec:
- Standard mode: {gameId}.setup.jsdos (full game + setup autoexec)
- Sockdrive mode: .jsdos-setup/ directory alongside .jsdos/
- Both bundles share the same game files; only the autoexec differs
Frontend changes:
- Router strips query params from hash so ?setup=1 doesn't leak into id
- GameDetail shows a "Setup" button between Play and Edit (only when
game.has_setup is true), navigating to /play/{id}?setup=1
- Play.svelte detects ?setup=1, loads setupBundleUrl() instead, and
shows setup-specific overlay text
Persistence is handled automatically by js-dos v8 via the built-in
auto-save mechanism (ci.persist() → browser OPFS), so any config
changes made via SETUP.EXE survive across sessions.
Flow when auto-search finds nothing:
1. User types a title → presses Enter/clicks button
2. System searches IGDB with that title
3a. Results found → shown as selectable cards
3b. No results → warning + amber 'Upload anyway as xxx' button
4. Button label changes: 'Search' → 'Upload' after manual search
Also changed Enter key behavior: first press searches, second
press uploads (if no results after manual search)
Quarkus defaults to 10MB max body size. DOS games like
Warcraft 2 (50-100MB) were silently rejected. Added:
- quarkus.http.limits.max-body-size=200M
- quarkus.resteasy-reactive.multipart.input-part.max-size=200M
Upload flow is now:
1. Click +Upload → select a .zip file
2. IGDB is auto-searched with the filename
3. If matches found → show results as selectable cards + fallback
custom title search at the bottom
4. If no matches → show 'no matches' + manual title + Upload btn
+ a fallback 'Use filename: xxx' button
5. Clicking a result uploads immediately with that game's title
(so IGDB auto-scrape picks it up correctly)
6. Cancel button to dismiss
Completely new approach:
- After unzip, check if extractDir has exactly one entry (a directory)
- If so, move all its contents up and delete the empty folder
- This means game files are always at the bundle root (c:\)
- No more cd/subdirectory handling in config builders
- No more path separator conversions (forward/backslash)
- Removed splitPath() helper entirely
- Config builders are now trivial — relExe is always just a filename
Removed:
- injectDoomConfig() — WAD-detection and WASD config injection
- buildDoomDefaultCfg() — Doom config file generator
- All calls to injectDoomConfig in both bundle paths
Fixed:
- buildJsdosJson() now also uses splitPath() helper to handle
backslash separators (was using lastIndexOf('/') only)
- Extracted shared splitPath() method used by both
buildJsdosJson and buildDosboxConf
No more game-specific hacks. Just clean config generation.
extractDir.relativize() returns paths with native Linux forward
slashes. DOS requires backslashes. Changed .replace('\', '/')
to .replace('/', '\') and updated buildDosboxConf split logic
to also check for backslash separator.
When a ZIP contains game files in a subdirectory (e.g. doomiido/),
findMainExe() correctly finds the executable but the bundle autoexec
was using just the filename, causing DOSBox 'Illegal command' error.
- Use extractDir.relativize() to compute the relative exe path
- buildDosboxConf() now adds 'cd dirname' before running the exe
- buildJsdosJson() uses 'cd dirname && exe' for multi-line script
- Fix applies to both sockdrive and standard bundle paths
The dos.zone DEFAULT.CFG uses \r\n (DOS/CRLF) line endings.
Our injected config used \n (LF/Unix). While fgets() reads
both, the \r character stays in the buffer and the Doom
parser may behave differently when it's absent. Matching
the exact byte-for-byte format that works on dos.zone.
The missing piece — dos.zone's bundle has .jsdos/jsdos.json
which tells js-dos v8 how to configure the emulator (autoexec
command, autolock=true, etc.). Without it, js-dos may apply
different defaults that don't match our dosbox.conf.
Also simplified dosbox.conf to just the essential sections
and removed mapperfile=mapper-jsdos.map (not bundled).
Keeps usescancodes=true, autolock=true, SB16 audio.
Previous injectDoomConfig used Files.list() which only checks the
top-level directory — if the WAD was in a subdirectory, detection
failed silently and no config was written. Switched to Files.walk()
for recursive search.
Also:
- Write BOTH DEFAULT.CFG AND DOOM2.CFG (Doom II reads DOOM2.CFG
first as game-specific config, falling back to DEFAULT.CFG)
- Always overwrite (don't skip if file exists — the ZIP might
contain a stock DEFAULT.CFG with arrow-key defaults)
Root cause: Dosbox.conf was missing the [sdl] section with
'usescancodes=true' — without it DOSBox doesn't translate
keyboard scan codes and WASD keys don't register as game input.
Fix:
- Generate a complete dosbox.conf matching js-dos v8 standards
(all sections: sdl, dosbox, cpu, mixer, render, midi,
sblaster, gus, speaker, joystick, serial, dos, ipx, autoexec)
- Key setting: usescancodes=true + mapperfile=mapper-jsdos.map
- Uses svga_s3 machine type with SB16 audio (same as dos.zone)
Bonus: Auto-detect Doom-engine games (DOOM.WAD / DOOM2.WAD)
and inject a DEFAULT.CFG with WASD controls:
W=forward, S=backward, A=strafe-left, D=strafe-right
Arrows=turn, Ctrl=fire, Space=use, Alt=strafe, Shift=run
Mouse enabled for looking
Note: Existing uploaded games still have the old dosbox.conf.
They need to be re-uploaded to get the fix.
Game Detail:
- Year/genre badges and developer/publisher info moved from
the info column to the cover column (below the cover image)
- Edit mode unaffected — fields remain in the form on the right
- Added CSS spacing for meta/dev in cover section
Library upload:
- Removed the always-visible title input field
- After selecting a .zip, a modal dialog appears with two options:
1. 'Use filename as title' — uploads immediately with filename
2. Custom title input + 'Upload' button
Plus a Cancel button
- Modal is dismissible by clicking outside or Cancel
The info-section grid column (1fr) was expanding to fit wide content
like long game titles in Press Start 2P font (each character ~24px).
Added min-width:0 on grid children to prevent overflow, and
word-break:break-word on text elements as a safety net.
Global:
- Viewport meta already present; added -webkit-text-size-adjust: 100%
- Container padding reduces to 12px on mobile (was 24px)
- Smaller heading sizes (h1: 1.5rem, h2: 1.25rem)
- Buttons get min-height 40px for touch targets
- Inputs forced to 16px font-size to prevent iOS zoom
- Thinner scrollbar on mobile
Header:
- Logo text shrinks to 1rem on mobile, icon to 28px
- Header padding reduces to 12px
Library:
- Toolbar stacks vertically on mobile, full-width inputs
- Grid forced to 2 columns on narrow screens (480px), reduced gap
GameCard:
- Smaller info text, padding, badge on 480px screens
GameDetail:
- Cover section capped at 200px width on mobile
- Media thumbnails shrink to 160x90
- Scrape header stacks vertically with full-width buttons
- Edit rows stack vertically on mobile
Play:
- DOS container caps at 50vh on mobile, smaller border-radius
- Overlay text/icon sizes reduced, more compact layout
- Backend: Add GET /api/games/{id}/download endpoint (ZIP streaming)
- Frontend: All videos now shown in media row alongside screenshots
- Click any media thumbnail to load it into the media container
- Videos show YouTube thumbnail, screenshots show image preview
- Active thumbnail has green border highlight
- Download button between Edit and Delete triggers ZIP download
- Early return: if no media, the entire section is hidden
- Search now filters to DOS platform only (platform ID 13)
- New fetchVideos() queries IGDB game_videos endpoint for YouTube IDs
- New fetchScreenshots() queries IGDB screenshots endpoint for images
- autoScrape and applyIgdbId both fetch videos + screenshots after match
- Upload auto-save also triggers when videos/screenshots found
- GameDetail: embed first YouTube video + scrollable screenshot gallery
- Handles missing media gracefully (section hidden entirely if neither exists)
- New IgdbService: Twitch OAuth2, IGDB API v4 search, cover download
- Upload auto-scrapes IGDB after extracting game ZIP
- GameDetail page: 'Auto Scrape' + 'Search' buttons + result picker
- Upload dialog: optional title field (defaults to filename)
- Jackson SNAKE_CASE naming to match frontend expectations
- IGDB status endpoint to check credentials
- Replaced Go stdlib server with Quarkus (RESTEasy Reactive + Jackson)
- 7 Java classes: Game POJO, GameService (JSON file I/O), 4 REST resources, static file serving
- Same JSON-per-game storage, same ZIP upload + bundle creation
- Same Svelte frontend (unchanged), built into the JAR via maven-resources-plugin
- Multi-stage Dockerfile: Node → Maven → JRE runtime
- dos-container div always mounted (fixes circular dep: container needed for start, was gated on running)
- Overlay covers the empty canvas while booting: Loading → Booting (CDN) → Running
- No intermediate "Start Game" screen — emulator auto-starts immediately
- Error state shown inline if something fails
- Stop button + back arrow both kill emulator and return to detail
- Emulator auto-starts when Play page loads (no intermediate launch screen)
- Added ⏹ Stop button while game is running
- Back arrow and Stop both kill the emulator (js-dos CI.exit())
- Cleanup on unmount prevents background emulation
- Loading state shown while js-dos CDN loads
- Manual "Start Game" fallback if auto-start fails
Hermes Agent
David Alvarez