First, there is no such version of ROS 4.90, but i guess it is a typo.
As for the backup, see the below topic, it could help you:
http://forum.mikrotik.com/t/backup-with-wireless-card-configuration/43296/1
First, there is no such version of ROS 4.90, but i guess it is a typo.
As for the backup, see the below topic, it could help you:
http://forum.mikrotik.com/t/backup-with-wireless-card-configuration/43296/1