I stole this directly from http://support.popcornhour.com/article.aspx?id=1011

1. Connect your Popcorn Hour A-100 to the Composite input of your TV
2. Boot up and you should see first boot up logo
3. Wait until the screen goes blank
4. Press TV Mode + 1 (Press TV mode key, release and follow by key 1 and release) for NTSC or TV Mode + 2 (Press TV mode key, release and follow by key 2 and release) for PAL
5. If you see the color menu in Composite try to set the HDMI output at Setup → Audio/Video and do a save.
6. Connect your Popcorn Hour A-100 to an HDMI input of your TV.
7. Power up Popcorn Hour A-100

1. Use the ENTER key NOT the play key to start and ISO file playing.

URL for adding a NFS share:

nfs://10.0.0.2:/mnt/raid/space

URL for adding a samba file share:

smb://10.0.0.2/david

I simply left it in DHCP mode, and added the MAC address to my DHCP server so it would dish out the same IP address every time. That way my NFS sharing can be limited to that single IP address and not pose any security issues with floating or wide open shares.