Getting started

From an old disk image to a file you can read.

You can explore FatFloppy with just a disk image. A floppy drive and Greaseweazle are only needed for working with physical disks.

On this page: Installation | Your first file | Working copies | Making changes | New images

Installation

FatFloppy runs on modern Windows, macOS, and Linux computers. Download a package from the version 0.2.0 release, published 13 September 2026. The project is still in alpha; the installation instructions cover platform-specific setup.

System	Package	Getting it running
Windows	64-bit installer or portable ZIP	Windows 10 or later. Run the installer, then launch FatFloppy from the Start menu. A portable ZIP is also available.
macOS	DMG disk image	Choose a build for Apple Silicon or Intel, then drag FatFloppy into Applications. The app is unsigned; see the installation instructions for the first launch.
Linux	AppImage	Make the downloaded file executable and run it. If FUSE is unavailable, the README gives an extract-and-run alternative.

Running from source

You'll need Python 3.9 or later. In an activated Python virtual environment, run:

git clone https://github.com/briskspirit/FatFloppy.git
cd FatFloppy
python -m pip install -e .
fatfloppy

The installation brings in PyQt6, the Greaseweazle Python tools, and crcmod. You do not need Greaseweazle hardware to open image files. Developers can install ".[dev]" instead of . to include the test and lint tools.

Open an image and extract a file

1. Open the image. Click Open Image, or choose File > Open Disk Image File. Select your image; FatFloppy examines its contents to identify the container and filesystem.
2. Check what opened. The Disk Information panel shows the detected format, physical geometry, and filesystem. The directory tree sits on the left and the files appear beside it.
3. Look inside a file. Double-click its name, or select it and click View File. Both the text and hex views are filled; switch tabs to see the other representation.
4. Take a copy out. Select the file and click Extract. Choose a name and destination on your computer. For several selected files or a directory, choose the folder they should go into.

You can also drag files out to your computer's file manager. Extraction copies their contents without removing them from the disk.

A directory full of unfamiliar short names is quite normal. The formats guide explains Commodore file types, RT-11 allocation, and the different rules these filesystems follow.

Make a working copy before editing

Keep the original image, and experiment on a copy. You can duplicate it in your computer's file manager, or open it in FatFloppy and choose File > Save As... before making changes. Give the copy a new name and keep the same output format to retain the original container. After a successful save, FatFloppy opens the new copy.

Add File, Delete, and New Folder act on the open disk. There is no final “save all changes” step that lets you abandon those operations later. The text editor has its own save and discard buttons.

Save As... can also convert between compatible image formats. A conversion carries the disk's sectors across, but a plain IMG cannot retain every piece of information in an archival container. Keep the source archive alongside the converted image. Teledisk TD0 archives themselves are read-only.

Add, edit, and remove files

To do this	Use this
Add a file	Open the destination directory and click Add File. Select a file from your computer, then accept or change the suggested disk filename. Dragging files into the file list imports them with names adapted to the target filesystem.
Edit text	Open a text file, edit it, and click Save Changes. Discard Changes restores the text as it was when opened. The editor preserves the original LF or CRLF line-ending style.
Inspect binary data	Use the Hex Viewer. It is read-only. A file identified as binary also gets a read-only text preview.
Remove a file	Select one or more entries, click Delete, and confirm the deletion. Deleting a directory includes its contents.
Create a directory	Click New Folder on a filesystem that supports directories. CP/M, HDOS, and RT-11 do not have ordinary nested folders; Commodore D81 uses partitions.

Some disks open read-only. The filesystem and the image container both matter: a writable filesystem inside a TD0 archive still cannot be edited in place. See the support table for the exceptions.

Create a blank image

Click Create Image. Choose the Disk Size and a named Format, then select a directory, filename, and compatible image type. Set a volume label where the filesystem supports one. FatFloppy creates, formats, and opens the new image, ready for files.

A named profile is a good starting point: two disks with the same diameter and capacity can have different sector layouts. The advanced parameters are useful when you already know the geometry of a particular machine.

For a closer look at the window and its disk map, continue to the visual tour.