Ok, I built the floppy image now. dd'ed it on a floppy and powered my IBM PS/1 up. Despite some nasty sounds of the HDD bearings that went away after 30 seconds, the floppy does not boot on this machine. Just a black screen. 386SX-25 2MB RAM. Maybe 2MB RAM too less, but I thought at least something will happen. :-)

There seems to be an 8 meg image here: https://github.com/luke8086/gentleos32/releases/download/202...

For PS/1 you'll need the 16-bit version from https://github.com/luke8086/gentleos. A floppy image is provided in releases. Note you only need to copy the first 64KB, the rest is just padding for emulators.