Keyboard configuration

I use a small keyboard (without numeric keypad) and I have these settings to make it work:

$_external_char_set = "utf8"
$_internal_char_set = "cp850"
$_layout = "keyb-user"
$_rawkeyboard = (1)
$_X_keycode = (off)
AND I use keyb inside FreeDOS.

It looks to me that I am "over-configuring" in that some of these do not make sense in presence of others.

Can anyone send me some light on the matter?

thanks,
ALain