Hi,
I’ve been struggleing with getting my model a rpi up and going. I got a couple of these boards by mistake (the seller had a picture of the 'b’s but sent 'a’s instead) and I don’t have a usb hub so I’ve been having some issues troubleshooting as I’ve been limited to using either keyboard or wifi dongle. I checked that my dongle is supported by rpi, it’s the DX original nano. I see that when it boots up the rpi discovers it and names it Ralink.
I’ve been trying out literally all the /etc/network/interfaces configurations I’ve come across but every single one of them renders the message
and moves down checking eth0.
Does anyone have some tips on what I can do to get this up? I don’t know much linux so please bare with me here… 
The SSID is being broadcasted and password does not contain any special characters.
As a sidenote, I have a model b which works fine as I connected it with ethernet and then plugged in the wifi dongle.