The original Mac floppy disk format was MFS, for Macintosh File System, and it is only used for 400K single-sided floppies – the only kind of floppy drive supported by the original Macintosh, the Mac 512K Fat Mac, and the Lisa 2 (a.k.a.

I haven't had trouble finding 'tested working' used 3.5' floppy drives on eBay to plug into my KryoFlux and Greaseweazle for under $30 Canadian including shipping from Europe.Earlier today in the Apple Macintosh Enthusiasts Facebook group, Charles Lott asked if an OS X Mac with a USB floppy drive could write disks that a Mac running System 7 could use. There's a Purchase a Greaseweazle page on the GitHub project's wiki and I managed to get a bare Greaseweazle V4, delivered, for about $36 Canadian. though the Flu圎ngine is a DIY 'solder a connector or some pin header onto an FPGA dev board and flash it using Windows software' project and the dev board is suffering from the chip shortage. (The help for KryoFlux's dtc CLI also lists a -we=2 option to set an erase mode of 'wipe' when writing which may have a similar effect to gw erase followed by writing such an empty disk image.)īoth the Flu圎ngine and Greaseweazle can be had quite cheaply as far as such boards go (you'll still need a floppy drive, possibly cabling, and possibly an external power supply, depending on the board and whether you buy a bundle).

The Flu圎ngine software recently gained filesystem support and supports Greaseweazle hardware too, so its new fluxengine format command may do what you want.Īlternatively, you could see if something like gw erase followed by writing an image of an empty disk would do what you want.

should be physically capable of it (they do deal in raw flux) and it's just a matter of software support. According to ArchWiki, the ufiformat tool can command those cheap USB floppy drives to perform a low-level format.Īside from that, while I can't vouch for it myself, since I've only ever used mine to read floppies, archival/forensic USB floppy controllers like the KryoFlux, Greaseweazle, Flu圎ngine, etc.

Formatting 720k floppy disk in window 7