FluxForge is a free Windows desktop app for backing up, preserving and writing floppy disks with a Greaseweazle USB floppy controller. Read Amiga, Atari ST, IBM PC and Commodore 64 disks to ADF, ST, IMG and D64 images, capture genuine raw flux to SCP for long-term preservation, and write images back to real floppies, all without opening a terminal.
FluxForge is a modern graphical front end for the official Greaseweazle host tools (gw.exe). It
installs and updates those tools for you, detects your board, shows a live track map while it works,
and tells you the truth about every disk: what was recovered, what wasn't, and why.
FluxForge is an independent project and is not affiliated with the Greaseweazle project. Version 1.0, tested on a Greaseweazle V4.1 with a 3.5" PC floppy drive.
- No command line. One-click, user-approved install of the official Greaseweazle host tools, with no Python, no PATH editing and no administrator rights.
- Preservation first. Raw flux captures always use
--raw, so the SCP file holds what the disk actually contains, not a "cleaned up" regeneration. - Honest results. A read is only marked Succeeded when every sector is proven decoded. Worn disks show as Partial with exactly which tracks failed; a write only counts once it is verified.
- Catches the wrong format. If a disk holds sectors your chosen format doesn't define (such as an Atari ST 800K, 10-sector disk read as 720K), FluxForge says so and suggests the right format, instead of silently dropping data.
- Check a disk against an image. Verify reads a disk and compares every sector with an image, and tells apart sectors that differ from sectors the drive couldn't read.
- A catalogue of your collection. Every disk you read lands in the Library with its SHA-256 fingerprints, where it came from and how it went, ready to search, tag and re-check.
- Recover without touching the disk again. Decode any saved raw capture into a sector image with a different format in Image Studio. Fragile disks only need to be read once.
- Safe firmware updates. See whether your Greaseweazle's firmware is current and update it with a typed confirmation, a check of the result and a link to the official recovery guide.
| Read a disk | Verify against an image | Library |
|---|---|---|
 |
 |
 |
| Image Studio | Drive Tools | Activity |
 |
 |
 |
Every feature below has its own full-size screenshot, all taken from real runs on a Greaseweazle V4.1.
- Verify: read a disk and compare it sector by sector with an image or a raw capture.
- Library: a searchable catalogue of your disks and images, filled automatically as you work.
- Firmware assistant: check and update the Greaseweazle firmware from Drive Tools.
- Clearer Activity list, the COM port in use shown in Settings, and a refreshed blue look to match the logo.
Upgrading from 0.1.0? FluxForge offers the update itself (Settings, About), and your existing job history is added to the Library the first time you open it.
- Preservation capture: raw flux to
.scp, with an optional decode check of the format while reading. - Sector images: Amiga
.adf, Atari ST.st, IBM PC.img, Commodore 64.d64. - Live track map for both sides of the disk, with the current track animated, plus retries, missing sectors and per-track detail.
- SHA-256 fingerprint of every image, and a full job log with the exact
gwcommand and output. - Never overwrites a file. Cancelled or failed reads are kept and clearly labelled
(INCOMPLETE).
- Guarded write flow: choose the format explicitly for ambiguous images, tick an overwrite acknowledgement, then confirm.
- Verification is on by default, and the track map animates as each track is written and verified.
- Interrupted writes are reported as "disk state unknown", never as success.
- Reads the disk and compares it sector by sector with an
.adf/.st/.img/.d64image, or with a raw.scpcapture (decoded with your chosen format first). - The track map marks each track as matching, different, unreadable, or not comparable because the image itself has no data there (sectors that were unreadable when the image was made).
- Lists every problem sector by cylinder, side and sector number. Read only: nothing is written to the disk, and the readback is deleted once compared.
- One click from the Write result: "Verify against this image".
- Every successful read and decode is added automatically, with the job that made it (date, result, format). A decode joins the disk its raw capture came from. Existing history is imported the first time you open the Library.
- Give each disk a title, system, condition (good, worn, damaged), tags and notes, and search across all of them, plus file names and SHA-256 fingerprints.
- Check files re-hashes images and tells you if one has changed or gone missing since it was catalogued. Verify results are recorded against the image they were compared with.
- Add images you already have. A capture and an image with the same name in the same folder are kept together as one disk.
- One click to verify a disk against an image, write it, or decode a capture in Image Studio.
- Images stay where you saved them; the Library (a local SQLite file) only stores paths, hashes and your notes. Removing an entry never deletes a file.
- Turn an existing
.scpflux capture into an.adf/.st/.img/.d64image with any supported format. - One-click "Decode as …" when FluxForge detects that a different format fits the capture better.
- Installs the official Windows release from GitHub after you approve it, with HTTPS-only download, digest check, safe ZIP extraction and a self-test.
- Version management: a daily update check that always asks first, "skip this version", and installing or switching to older Greaseweazle versions if you depend on one.
- Use your own existing
gw.exeinstead, or import a downloaded ZIP offline.
- Drive speed check (RPM) with a plain-language health verdict.
- USB bandwidth test between the PC and the Greaseweazle.
- Seek the heads to any cylinder, reset the board, and view the drive timing settings.
- Head cleaning with a cleaning disk, and disk erase, both behind clear confirmations.
- Firmware assistant: shows the board's firmware next to the latest official release and updates
it with
gw update, pinned to the version you were shown. It needs a typed confirmation, can't be interrupted once started, confirms the new version with the board afterwards, and links the official recovery guide. The bootloader is never touched. - Every tool run is recorded in Activity.
- Shows host tools, device and firmware as separate statuses (for example "Greaseweazle V4.1 on COM6, firmware 1.6").
- Plain-language help for common hardware errors, such as "Track 0 not found" (a straight cable usually means drive B).
- Activity history with searchable jobs and exportable text reports (with optional path redaction).
| System | Formats (Greaseweazle diskdef) | Image |
|---|---|---|
| Commodore Amiga | AmigaDOS DD 880 KB (amiga.amigados) |
.adf |
| Atari ST | 360 KB, 720 KB, 800 KB (10 sectors), 880 KB (11 sectors) (atarist.*) |
.st |
| IBM PC / MS-DOS | 720 KB DD, 1.44 MB HD (ibm.720, ibm.1440) |
.img |
| Commodore 64 | 1541 (commodore.1541) |
.d64 |
| Any disk | Raw flux, no decoding | .scp |
More of Greaseweazle's 150+ disk definitions (Apple II, Acorn, Amstrad, MSX, PC-98 and others) are
planned. Copy-protected disks should be captured as raw flux (.scp).
- Windows 10 (22H2) or Windows 11, 64-bit
- A Greaseweazle board (V4/V4.1 tested) and a floppy drive. A standard 3.5" PC drive reads Amiga and Atari ST DD disks
- The Greaseweazle host tools, which FluxForge installs for you
- Download FluxForge.Desktop-win-Setup.exe from the latest release.
- Run it. FluxForge installs just for your Windows user (no administrator rights needed) and adds a Start menu shortcut. Prefer not to install? Use the Portable zip from the same page.
- FluxForge keeps itself up to date: Settings → About → Check for FluxForge updates.
Windows may show a SmartScreen warning for new releases while the app builds its reputation. Choose More info → Run anyway. Uninstalling FluxForge keeps your disk images, settings and history.
- Run FluxForge. On first launch, choose Install official host tools…, review the release and approve it.
- Connect your Greaseweazle by USB. FluxForge detects the board and firmware.
- Click Back Up Disk, pick the disk format, and choose Preservation (raw flux) for anything irreplaceable. If reads fail with "Track 0 not found", set the drive to B.
- Open Library to name the disk, note its condition and add tags. Every backup lands there automatically.
- After writing an image to a floppy, use Verify against this image to read it back and compare every sector.
Is FluxForge a replacement for Greaseweazle?
No. FluxForge drives the official Greaseweazle host tools (gw.exe) and adds a user interface,
safety checks, a track map, job history and image management on top.
Raw flux (SCP) or sector image (ADF/ST)? For preservation, capture raw flux: it keeps everything on the disk, including copy protection and timing. Sector images are smaller and work directly in emulators such as WinUAE, Hatari and VICE, and on Gotek / FlashFloppy. FluxForge can make a sector image from a raw capture later, without the disk.
My Atari ST disk "struggles" in other tools. It may be a 10-sector (800K) or 11-sector (880K) disk. FluxForge detects this and suggests the matching format.
How do I check that a copied disk is good? Use Verify: choose the image the disk should match and FluxForge reads the disk and compares every sector. It lists any sector that differs or can't be read, and nothing is written to the disk.
Does the Library move or copy my images? No. Images stay where you saved them. The Library is a small database in FluxForge's data folder that stores only paths, SHA-256 fingerprints and your notes. Check files tells you if an image has changed or gone missing.
Can FluxForge update my Greaseweazle firmware? Yes, from Drive Tools → Greaseweazle firmware. It shows your version next to the latest official release and only updates after you type UPDATE and confirm. It never touches the bootloader.
Can I use an older Greaseweazle version? Yes. Settings → Host tools versions lists every stable release; install or switch between them.
Developers: see CONTRIBUTING.md for building from source, testing without hardware and the project layout.
Found a bug or have an idea? Open an issue. Tried FluxForge with your own Greaseweazle? A quick hardware test report helps a lot, even if everything worked. When reporting a problem, attach the job report from Activity → Export report. If FluxForge saved one of your disks, you can buy me a coffee ☕
Developed by Chris Freeman (@freemchr).
FluxForge is free and open source under the MIT License. It is provided as is, without warranty: always keep a raw capture of disks that matter before writing to them. Greaseweazle and the other components FluxForge uses keep their own licenses; see THIRD-PARTY-NOTICES.md.