Should be able to get the user guide from RM Support?
Thanks for the reminder, I found that page a long time ago but never got round to reging ! However a revisit now shows a new pdf there that is freely available and Lo! it describes the three ports as
" 1.2.1 Power USB Ports
When you press Power USB button under off mode, you can charge external USB devices with power cable connected."

No mention of SATA, no worries - I dont have any SATA devices !
This USB button is a button alongside the power-on button such that when the lappy is powered down the Power USB Ports can be enabled for charging ext devices.
So mystery solved and turns out no use to me LOL!
PS Just discovered it has an HDMI port as well, that could have a use.
Thanks for all your promptings guys, I learned something today
