Diskette Toolkit

Read, write, format and test floppy disks and disk images for the Atari ST and many other 3.5" systems (PC, MSX, Mac, Amiga, Amstrad PCW, MINIX, Linux…) on Windows. Inspired by the Atari program FastCopy: a live sector map shows every track being read, formatted, written and verified.

Česky: návod je v souboru NAVOD.txt, přehled mechanik v docs/drives-cs.png.

Get the latest ZIP from Releases, unzip it anywhere and run DisketteToolkit.exe (administrator rights are needed for direct drive access). No installation — only .NET Framework 4.8, which is part of Windows 10 and 11 (Windows 7 SP1 / 8.1 need it installed).

Try it without hardware: DisketteToolkit.exe --demo (simulated drives).

See also: Privacy · Code signing policy

Fixes, mainly safety on damaged disks and a clearer window:

• Greaseweazle never silently overwrites unreadable sectors with zeros: the "keep data" write test refuses, the file-system repair asks and says whether data would be lost
• Greaseweazle: density from the measured data rate, a damaged last track no longer halves the backup, flux backup to .hfe works, 32-bit gw.exe on Windows 7, Akai S1000/S3000 formats
• Rescue refuses to mix a different disk into an unfinished rescue image; images are saved via a temporary file
• The fdrawcmd.sys installer's signature is verified by Windows
• The result of every operation is shown under the map in colour; bad and weak sectors are marked with symbols, not only colour; keyboard shortcuts; grouped drive diagnostics; "repair now" after a surface test

• Drive diagnostics (Greaseweazle, internal drive + fdrawcmd.sys): drive speed with wobble and a live gauge for turning the speed trimmer, warm-up test, sensor check, head to track 0 / 79 / sweep, step accuracy test, head cleaning, repeated track read (dirty head or damaged disk?), USB bandwidth test, flux histogram per track
• Rescue a bad disk: many retries per unreadable sector, continue in another drive (only missing sectors are read), and at the end advice whether another drive can still help or the spot is lost
• Rescue sectors from flux: open a Greaseweazle .scp, decode it with the built-in MFM decoder, combine captures of the same disk from several drives into one image
• Error reason for every failed sector in the map, read history (disk or drive?), disk grade A/B/C after a write test
• Safer Greaseweazle writes: USB bandwidth is checked first, a write that would stop mid-track is not started
• The FAT check leaves boot loaders and other non-FAT disks alone

Tested on real hardware with a Greaseweazle V4.1 (NEC, Samsung and ALPS drives; HD and DD disks) and a Sony USB-FDU. The diagnostics on an internal drive with fdrawcmd.sys are not verified on real hardware yet.

On some desktop PCs with an AMD AM5 board (B650, X670, X870) the USB controller feeds slow USB devices too slowly for Greaseweazle writes (reading works). Use another computer or an add-in PCIe USB card; Drive diagnostics → USB bandwidth test shows whether your port is fast enough.

The program downloads gw.exe and fdrawcmd.sys itself when you need them.

• Backup to image (.ST, .MSA, .IMG, .DIM, .ADF, flux .SCP/.HFE) and write images back with verification
• Format profiles for Atari, PC, MSX, Mac HFS, Amiga CrossDOS, Amstrad PCW, MINIX, ext2
• Batch backup: a box of disks one after another into numbered images (disk-001.st, disk-002.st…)
• Drag an image file onto the window to open it
• Drive diagnostics (internal drive + fdrawcmd.sys, Greaseweazle): speed with wobble and a live gauge for adjusting, sensor check, head moves and cleaning, repeated track read (dirty head vs. damaged disk), track layout listing (fdrawcmd.sys), warm-up and step accuracy tests, flux histogram and USB bandwidth test (Greaseweazle)
• Rescue a bad disk: many retries per unreadable sector, continue in another drive (only the missing sectors are read), advice whether another drive can still help, experimental bit voting from bad reads (fdrawcmd.sys); rescue sectors from saved Greaseweazle flux (.scp) with an own MFM decoder, combining captures from several drives
• Error reason for every failed sector in the map, read history that tells a faulty drive from a faulty disk, disk grade (A/B/C) after a write test
• Surface test (read-only, write test with restore, destructive) with a FastCopy-style map
• Experimental repair format (internal drive + fdrawcmd.sys): a defect on a track is covered by an extra sector instead of being marked bad in the FAT
• FAT12 check and safe repair (backup first, only changed sectors written, repairs of images go to a copy)
• Boot disks: FreeDOS, MS-DOS from your own Windows (diskcopy.dll), Amiga bootblock, Atari AUTO folder, RawWrite
• Image tools: open and extract files, check/repair, convert, create blank images
• Czech and English UI; add a language with a xx.lang file (Settings → Create a template for a new language)
• Command line: dtk.exe (Czech only for now)

I design, test and maintain Diskette Toolkit myself; the code is written with AI assistance (Claude). Every change goes through a pull request that I review and test before it is merged.

Bug reports and ideas are welcome in Issues. Please include the program version, Windows version, drive type and the log (right-click the log → Save log to file…).

Diskette Toolkit is free. If it saved your disks, you can support it on GitHub Sponsors or buy me a coffee on Ko-fi — it helps with test disks and drives. Thank you!

C# / .NET Framework 4.8. On Windows: dotnet build src/Gui/Gui.csproj -c Release. On Linux the build uses Mono reference assemblies (/usr/lib/mono/4.8-api); tests run with mono tests/bin/Release/net48/AtariFloppy.Tests.exe.

Diskette Toolkit does not collect or send any data about you or your computer. It only connects to the internet when you ask it to download an add-on, and then only to the official sources: GitHub (Greaseweazle Host Tools, api.github.com / github.com), ibiblio.org (FreeDOS for boot disks) and simonowen.com (fdrawcmd.sys driver installer). The Support development button opens Ko-fi in your browser.

Windows releases are going to be signed. Free code signing provided by SignPath.io, certificate by SignPath Foundation (application in progress).

• Builds come only from this repository, built by GitHub Actions (Build workflow).
• Committers and reviewers: Warysek
• Approvers (approve every signing request): Warysek
• All changes go through pull requests reviewed and merged by the maintainer.
• Add-ons that the program downloads on request (Greaseweazle Host Tools, fdrawcmd.sys, FreeDOS) are not part of the signed package and keep their own authors' signatures and licences.

GNU GPL v3. The FreeDOS boot sector embedded in the program is GPL v2 or later (see third_party/freedos). FreeDOS, Greaseweazle tools and fdrawcmd.sys are not bundled — the program downloads them from their official sources when needed.

© HoroPC (Wary)