Some progress, the load now boots 1.03b and I can find the NAS over the network but when I try to connect, it says there are no disks. I had the original PX4 configured with a 3 disk RAID-5 + spare, I am hoping I can possible retrieve stuff off the RAID volume so at the stage I only put the spare into the 1st disk position. But it isnt seen. Can I login at the Diskstation logn: prompt? If so what are the credentials? I'd like to see what the kernel actual sees as devices.