I've added the 1.59 com driver to a 950520 kernel source but a plain
   "stty < /dev/tty01 speed 57600" still hangs. :-(

It normally waits for carrier on open.  Try:

stty -f /dev/tty01 57600

which will open the serial port in non-blocking mode.  (Of course, on
last close it will be reset anyway.)