Data General One, EL backilght version

Hello. I have two similar Data General One, one with fixed disk, the other is the two-floppy version. Both came with no manual or disk unfortunately. Trying key combinations, I found the CMD-+ and CMD-- way to turn on and off the EL backlight, while CMD-LARROW and CMD-LARROW changes contrast. Any other useful key combination? At power on, the two floppy version doesn't boot (no floppy disks), but it shows a BIOS menu where we could format floppies and use the machine as serial terminal. Nice! I tried to format a floppy (720k or 1.44M) on both floppy, but with no luck, it doesn't work for some reason... :( No way to boot the machine from a previously written 720k disk. I don't understand what the problem could be. Any similar case anybody? The fixed disk version boots nicely the MSDOS still installed on the HD. It seems to work fine. This is a customized version for Allen-Bradley, it has also a big D-sub connector with three rows of pins on the back. It has also a memory expansion in the back slot, with a total of 640K+896K detected at boot (1.5MB total). No way to enter the BIOS menu however... maybe it's missing in this version? Anybody have a scan of the manuals or images of floppy? Thanks Andrea