Whether your workflow revolves around a Gotek, a Nalbantov USB floppy disk emulator, or the full Greaseweazle toolkit, you’re in the right place! I built this online Floppy Disk Image Converter around Greaseweazle tools to take the friction out of disk-image wrangling—just upload almost any 3½-inch or 5¼-inch image, click once, and within seconds you’ll have a pristine conversion or a neatly extracted archive, all while preserving every last bit of the original data.
For Yamaha Disklaviers using PianoSoft disks, you typically want the 720 KB DD option. Some later Mark IV disks use the 1440 KB HD instead, but the vast majority of early PianoSoft inventory uses 720 KB DD disks. If you’re performing other conversions on this tool, and you know what you’re doing, check the Advanced checkbox!
Floppy Disk Image Tool
How can I tell what options to select?
This depends on what kind of disk the image represents. For Yamaha Disklaviers using PianoSoft disks, you typically want the 720 KB DD option. Most PianoSoft disks of that era, and even most Clavinova disks, used this format.
If you’re converting files for use in a Nalbantov, you’ll generally want to convert to HFE files. Most of Nalbantov’s preconfigured USB sticks expect this format. If you’re converting files for use in a Gotek, you’re more likely want to convert to IMG files, unless you’re using custom firmware such as HxC or FlashFloppy.
However, if you simply want to read the files stored in the image, select ZIP. Please note that currently, when extracting files to a ZIP file, this tool can only read IBM formatted disks, and cannot read copy-protected Yamaha disks. You can still convert between formats, but you’ll be unable to copy the files off of the disks.
What can the tool do?
HFE ↔ IMG
Move images seamlessly between IMG and HFE formats and download a ready-to-use image. IMG is a very common format by emulators such as the Gotek, and also by virtual machines such as VirtualBox, VMWare, and QEMU. Nalbantov, as well as some other emulators, use HFE files instead.
Extract Files
Pluck files from any DOS or Windows floppy image and receive them in a tidy, ready-to-download ZIP archive. If you have an old floppy disk image or have downloaded one from the internet, this tool will let you read the contents! File extraction works on most IBM formatted disks that do not have copy protection.
SCP (Flux) → IMG/HFE
Transform Greaseweazle or KryoFlux flux dumps into fully usable disk images—or grab an extraction ZIP if that suits your workflow better.
Other Formats and Options
If you click the Advanced checkbox, you’ll be given access to the full range of types and formats available.
How does the tool work?
Keir Fraser’s Greaseweazle is the gold-standard toolkit for anyone who cares about magnetic-media preservation. The open-source combo of plug-and-play hardware and the cross-platform gw host tools lets you sample floppy disks at the raw flux level, then read, write, or convert them into just about any image you need—IMG, HFE, SCP, ADF, you name it.
With a single command (gw read … or gw convert …) you can resurrect long-lost data, bypass oddball copy-protection, and feed modern emulators or hardware like Gotek and Nalbantov. Behind the scenes, this tool is powered by Greaseweazle’s conversion tools.
Greaseweazle’s active GitHub community means fresh features (like HFEv3 support and flux visualization) land fast, and its permissive license invites tinkerers to extend or embed it in their own projects—exactly the kind of maker-friendly ethos we love.
Please also see my article on using a Greaseweazle to back up Yamaha PianoSoft disks for your Disklavier. This is still my preferred technique, whenever it’s an option.
What formats and extensions does this work with?
Because this is using Greaseweazle’s conversion tools, the following formats can be used. Check the Advanced button and they’ll appear:
Extensions
Formats
Spread the word
Finding this handy? Share the link on r/retrocomputing, Vogons, or with your synth-tech friends—every backlink helps other tinkerers discover the tool.