KUSBFloppy Formatter

Warning: Please be extremely careful and read everything below before using this software. It may cause data loss if used inappropriately.


This program is designed to format your thumb drive to the format supported by hardware floppy emulators. We have tested it with GoTek SFR1M44-U100K drives.

Please be aware that if you format your thumb drive via this program, the data on that drive will be irreversibly(most probably) lost.

Program supports 1.44M and 720K disks. It can directly write image to a thumb drive and dump any of the virtual floppies to an image file.

It is also possible to format a blank floppy and transfer files to it manually (UDisks2 is used for that under the hood).

Format Description

Thumb drive contains up to 1000 raw floppy images written one after another every 1572864 bytes (1.5 MiB). Thus image n*(counting from zero) is located at offset *n * 1572864.

System requirements

  • Interacts with UDisks2 via DBus API
  • Written in Python 3.5. May work on an earlier version but this is not guaranteed
  • Uses Qt5 and PyQt5
  • You will need to have direct write access to the devices you use with this program (in Ubuntu you will have to add yourself to 'disk' group)
  • To retrieve device list lsblk is used
  • To create floppy-disk image mkfs.msdos is used

License information

Uses Qt5 https://www.qt.io/

Uses PyQt5 https://www.riverbankcomputing.com/software/pyqt/intro

Built-in icons by http://www.fatcow.com/free-icons

This program is licensed with GNU GPL v3

Installation and startup

  • If you're using Debian, Ubuntu or some derivative of them -- use packaged version
  • If you are unable to use packaged version follow instructions:
    • Make sure that your system has everything stated in System Requirements above
    • Download package for other platforms
    • Run it with python 3. In console it should look like "python3 kusbff_1.0.1.zip"



  1. Added progress bar for mass formatting.
  2. Fixed work with new lsblk versions.
  3. Allow editing image label from main interface(double click image name).
  4. Fixed inability to format images without changing device.


  1. impossible to format images starting from index 99.
  2. Incorrect numbering of images.