Yes JMke,F6 still remains mystery(if i don't press it,i still get an option after while to specify device ("S"),with "handmade" bootable floppy.EVERYHING IS WORKING;FASTER AND BETTER(at least for me me;that's what's counting,right?).
Greetings from sunny Croatia;)

"if i don't press it,i still get an option after while to specify device"
ah, a stuck key then? ;)

Maybe,but i can live with that.
Thanks again,JMke,for your time&patience;)
...and other guys,too:D