r63429, real HW. There is "USB-FDD Legacy Emulation" (see SAM_7751) BIOS setting on my Toshiba Satellite A50-101. If I set it to Enabled, ROS will never boot (see SAM_7711 for ROS (Debug) and SAM_7750 for ROS (Screen) bootmodes). It was stuck for several minutes each time I took the picture.
With USB-FDD emulation disabled, ROS loads FLOPPY.SYS immediately without any issue.