Dreamcast VMU root metadata documents the FAT start at block 254. This recovery ignores only that two-byte field during pre-validation, verifies the physical FAT at block 254 plus the documented directory chain and every other fixed root invariant, then restores one and only one byte of FE 00. The complete image must reopen strictly.
Emulator & Retro Tools
Dreamcast VMU FAT Location Recovery
Restore exactly one damaged byte in the fixed little-endian root FAT-location value 254 only when the root marker, physical FAT, directory chain and all other fixed geometry already validate.
01 / Tool workbench
Use the runtime only when it is actually ready.
The application shell fails closed. An input interface is not enabled merely because a WordPress Tool record exists; the declared engine must be registered in the current build.
Session change summary
No output has been built in this session.
02 / Compatibility
Know the supported input before opening a file.
Compatibility fields are intentionally explicit. Missing values stay unclaimed rather than being filled with generic assumptions.
Accepted extensions
.vmu.vmd.bin.raw
Platforms
Dreamcast
Supported versions / editions
Raw 128 KiB Dreamcast VMU/VMS flash images using the documented root/FAT layout.
Input constraints
Exact raw VMU geometry; intact 0x55 root marker; valid physical FAT/directory chain; all fixed root fields except FAT location already exact; exactly one FAT-location byte differs from FE 00.
Known limitations
No CRC repair, no FAT-chain reconstruction, no directory-entry repair, no allocation repair, no game payload editing, no arbitrary metadata synthesis, and no multi-byte fixed-field repair.
Output / result
A new raw VMU copy differing at exactly one byte of the fixed root FAT-location field.
03 / Instructions
Use a reversible workflow.
File-oriented workflows start with an untouched original. Tool-specific instructions add only details documented for this utility.
- 01Keep the original
Preserve an untouched copy before creating or transforming binary output.
- 02Confirm scope
Match the file size, format, platform, and version to the support information on this page.
- 03Process locally
Use the runtime only when the page reports that its declared engine is loaded.
- 04Validate output
Compare or test the result before replacing any working source file.
Tool-specific steps
Choose a raw VMU image with a one-byte FAT-location-field defect. The actual FAT and directory structures must already prove where the system data resides before reconstruction is allowed.
04 / Privacy and processing
The processing mode is part of the product contract.
SaveEditor.com should state local processing only when the implementation truly keeps file contents in the browser. Server or hybrid processing must be disclosed just as clearly.
Declared mode
Browser local
Runtime state
Operational
Tool-specific privacy notes
Phase 54 reads only the explicitly selected local Dreamcast file in the browser. The sega-legacy-recovery-v1 runtime has no fetch, XMLHttpRequest, WebSocket, sendBeacon, FormData upload, server-side save processing, or telemetry path. The permanent 16 MiB per-file ceiling remains in force and the selected source is never modified.
05 / Troubleshooting
When a file is rejected, do not force it.
A rejection can indicate an unsupported size, format, version, platform, or byte sequence. Preserve the original and correct the input instead of bypassing validation.
Re-check the documented input type and browser size limit before retrying.
A generic converter does not imply support for every game-specific container, signing scheme, or serialization format.
Return to the untouched source instead of repeatedly processing a damaged or partially transformed file.
Known Tool issues
If the physical FAT/directory is corrupt, another fixed root field is inconsistent, or both FAT-location bytes are damaged, no output is produced.
06 / Verification
Support claims should be traceable.
The verification date, method notes, and public references are kept separate from marketing language so compatibility can be reviewed over time.
Last verified2026-08-10
Profiledreamcast-vmu-fat-location-recovery
Method notes
Verified with deterministic fixtures, every eligible one-byte corruption position, zero/multi-byte refusal, source immutability, exact one-byte scope, strict structural reopen, independent Python reconstruction, and full regression/source-package parity.
Public references
07 / FAQ
Questions to answer before editing.
These answers are generated from the Tool record and current runtime state rather than generic compatibility promises.
Is Dreamcast VMU FAT Location Recovery ready to use?
The Tool record is verified and declares an operational runtime. The page enables its input controls only when the declared engine module is loaded in the current build.
Does processing stay in the browser?
Yes for this declared mode. The loaded runtime processes the explicit input in the browser; Tool-specific privacy notes describe the exact scope and limits.
Should I keep the original file?
Yes. Keep an untouched source file until any generated output has been validated.
What if my input is rejected?
Use the validation message to correct the base, encoding, width, timezone, byte alignment, or size. The runtime does not guess through invalid input.
Related tools
Continue with the same tool family.
Only index-ready verified records from the same Tool Family are shown here.
Related guides
Read the guidance connected to this tool.
Only reviewed, index-ready Guides that explicitly reference this Tool are included.
Beginner
Save File Formats
Dreamcast VMU / VMS Save Formats Integrity & Troubleshooting Guide
A fail-closed Dreamcast VMU / VMS Save Formats troubleshooting guide for distinguishing representation problems from unsupported semantics and for selecting read-only integrity checks before any repair attempt.
Beginner
Backups & Safety
Dreamcast VMU / VMS Save Formats Backup & Identification Guide
A safety-first Dreamcast VMU / VMS Save Formats guide for identifying the intended representation, preserving an untouched source copy, and choosing only a verified compatible Tool.