When i instert the first floppy (kern.flp) everything goes smoothly and then it askes me for the other disk (mfsroot.flp)
How do you make your boot floppy disks? are you creating from a DOS or Windows system? or from other *nix?.In most cases you will need two files,"kern.flp and mfsroot.flp", but check README.TXT in the same directory to be sure.
From DOS/Windows :
D:\TOOLS\FDIMAGE.EXE
D:\FLOPPIES\BOOT.FLP
D:\FLOPPIES\MFSROOT.FLP
Assume that drive letter D is your CD-ROM drive.
Or you can do this D:\> tools\fdimage floppies\kern.flp A:
Repeat this command for each .flp file.

For other *nix use this :
#dd if=mfsroot.flp of=/dev/rfd0<<<This is device for freebsd and your device will be different depends on what Version *nix you have (I haven't check for mandrake)
It put a screen of text on my moniter and then stops...
Can you explain it about text?