Both the keyboard and the serial ports of the Inka should be connected in order
to use it with BRLTTY. The Inka itself is capable of communicating entirely via
the keyboard port, but the Linux kernel keyboard driver can't handle this.

In order to use the Inka with BRLTTY it is necessary to have the latest version
(dated 1998) of the firmware. If the Inka says either "mode 1" or "mode 2" at
the end of the version number after it's connected to a computer and turned on
then it has the necessary firmware. If it doesn't then it'll probably need an
upgrade. To do this, contact Baum and give them the serial number of the Inka
(which is printed on the under side of the device).

The newer firmware supports two modes of operation. Mode 1 uses the old Inka
protocol and transfers data at 57,600 baud with non-standard flow control. Mode
2 uses the new Inka protocol and transfers data at 19,200 baud with no flow
control.

The Inka defaults to mode 1. This is shown on the braille display when 
the Inka first initializes or after a soft reset.

Before running BRLTTY, change the Inka to mode 2 by pressing tl1+tl2+tr3 (which
is the digit 2 represented as a dot-six number). To return to mode 1 (neither
necessary nor desirable under Linux), press tl1+tr3 (which is the digit 1
represented as a dot-six number). The new mode setting is shown on the display
at the end of the line, after the version number and date of the firmware.