getting a not found error

"The requested URL /sub_crud/Configure/index was not found on this server."

I am trying to setup a development env on a Ubuntu PC. I have moved my code across and am able to get the program to start. The first line, after logging in is to run the index function in the Configure controller. This is failing with the error above. The actual path to my program is /var/www/html/sub_crud/application/controllers/Configure.php and in it I have a function called index(). I am thinking that there is some path I didn't set up for Codeigniter?

I have set $config['base_url'] = 'http://localhost/sub_crud'; in config.php
I have index.php at /var/www/html/sub_crud
$system_path = 'system';
$application_folder = 'application';

proof that an old dog can learn new tricks