Firebird Character Set

I´m trying to configure iso8859_1 character set for my fireruby
connection with no luck.

my database.yml looks like::

adapter: firebird
database: rails_app
host: localhost
charset: ISO8859_1

but it seem´s to ignore the charset param. Anyway, every doc/messages
related to fireruby looks very outdated, is it being supported/updated/
envolved at all ?

Thanks for any input!