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

and found the files still on the net.

let’s try it

un-7zipped it, and saw the makedisk.exe and the qnxdemo.dat the .bat said it worked on.

I (incorrectly) assumed the .dat was archived data the .exe would unpack and whip up into a bootable floppy so I…

dd bs=512 count=2880 if=qnxdemo.dat of=qmx.img

And mounted it as a virtual floppy. It booted/ran as shown in the pic, although did not see the NIC.

I imagine there’s a way to tell VMM to use something like an old NE2000 for the nic. Maybe another day.

oh, I see

I shut down the virtual and looked at the directory again. Hmm.

file qnxdemo.dat 
qnxdemo.dat: DOS/MBR boot sector... 

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.

  • Moonrise2473
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    1 year ago

    I don’t understand what’s the difference between directly using the file and DD. Copying 2880 512-byte sectors isn’t the same of copying an image?

    • Frater Mus@lemmy.sdf.orgOP
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      1 year ago

      I didn’t know what I was doing, or what I was working with. I made some assumptions that led me down an unnecessary path.