[BRLTTY] USB2Serial under Linux

[Hermann]

Hi,
I bought an USB2Serial adapter for my Notebook, because my braille display
(Alva Satellite 544) doesn't work at the USB interface (under Win  XP).
When I try to start the grml live CD with the notebook using this adapter,
the display doesn't work.
I type:
brltty -d usb:ttySx -t de
where "x" is the number of the serial port.
Btw. USB does work.
On the CD for the adapter there are several drivers for Linux, but it isn't
possible to install one of them when running grml as a live CD. Furthermore
I thought that Linux doesn't need drivers for USB2Serial.
Is there a way to get the braille display to work?
Regards
Hermann