Dunno if this is on-topic for the community or not.
Earlier today I was reminded of this old what-can-we-jam-onto-a-floppy challenge:
To demonstrate the OS's capability and relatively small size, in the late 1990s QNX released a demo image that included the POSIX-compliant QNX 4 OS, a full graphical user interface, graphical text editor, TCP/IP networking, web browser and web server that all fit on a bootable 1.44 MB floppy disk for the 386 PC. - wiki
It was a floppy boot image all along and the .exe was just dd-ing it over or whatever. Durrr. I set the .dat as the floppy image to boot in KVM and it came up fine. {edit: still with no NIC} I guess I shouldn't assume.
I was blown away by that when I booted it on my 486 way back when. I was not quite skilled enough to get networking going under linux, and the modem I had was hell to setup in windows (plug and pray!)... Under QNX everything worked out of the box, and it ran circles around Win 95. Really impressive