Hardware / KryoFlux



KryoFlux is a USB-based device designed specifically for the reliability and precision needed to acquire reliable low-level reads suitable for software preservation. This is the official hardware developed by The Software Preservation Society, an authority in authentic floppy disk imaging and preservation.
Source: https://www.kryoflux.com/


A short note for the DOS and CP/M community: You can save/duplicate any DOS or CP/M disk with the KryoFlux, but the so-called image occupies 30 to 40 MByte storage on your hard disk and this for each image! Why? Kryoflux can read MFM and FM sector images (*.img), but it cannot write them back to disk! This can only be done with KryoFlux stream files and these require a lot of disk space.

For this reason IMAGEDISK (IMD) by Dave Dunfield is the current standard for creating images! But also here the question: Will we still have real DOS computers with real floppy disk drives needed for IMAGEDISK in a few decades? I think not!

There is so much information about the Kryoflux, so I won't write anything more about it here (see „Information" below).

The advantage of the KryoFlux workflow is that you can basically use modern equipment and information technology and only need "one" old disk drive. It is much easier to keep a few NOS floppy disk drives (8", 1.2M, 360K, 1.44M, 720K) running than a whole DOS system.

I have tested the KryoFlux on an 8 inch, 360K and 720K drive. It does exactly what it should do.


If you want to use the KryoFlux, you must read the Quick Start Manual carefully. Please note in detail point no. 7! If you do not do this, Windows 10 will automatically install the wrong driver! At least this was the case with me.

If everything runs fine, the installation will take no more than 5 minutes. I run my Kryoflux on Windows 10 (with macOS and Parallels Desktop). Operates perfectly.

Duplicating an 8 inch floppy disk

At this site I will describe a special application. The operation of a Kryoflux to duplicate a standard CP/M 8 inch floppy disk (SS, SD, 77 tracks, 26 sectors, 128 byte/sector).

The basics for connecting an 8" floppy drive to a DOS PC are described here.

The following picture is a bit confusing, because here you can see four 8 inch drives, the complete power supplies and on the right side my 286AT testsystem. My iMac is not to be seen here, it stands two meters away. The Kryoflux is connected with a very long USB cable.

The upper NEC FD1165-FQ is connected to the 286AT as drive A:.

KryoFlux with 8 inch floppy and FDADAP adapter
KryoFlux with 8 inch floppy and FDADAP adapter

Both adapters are connected to a Mitsubishi M2896-63 (8 inch) drive.

First the backup is done via the well-known GUI in the format "KryoFlux stream files, preservation". Before the backup, you have to calibrate the drive, so that the 77 tracks are recognized correctly. That was it.

Writing to a freshly deleted disk (bulk erase) cannot be done with the GUI. This can only be done by command line.

DTC -fSSSD-77-26-128/track00.0.raw -w

path: .......... SSSD-77-26-128
first track: ... track00.0.raw
write: ......... -w

Quite simple, isn't it?

Kryoflux with 8 inch floppy and FDADAP adapter
Kryoflux and Windows 10 (macOS / Parallels)

Finally I tested the newly created disk on my 286AT with 22DISK and the NEC FD1165-FQ.


A1: standard CP/M format

... and done is the 1:1 8" floppy disk duplication ...

The duplication does not feel to take longer than with IMAGEDISK but it requires significantly more disk space.