Hi, I found a dutch site http://sepp.zutphen.nu/hdr1000 where someone explains how to upgrade/switch the hdd of the philips hdr1000 hard disc recorder. He explains how to read the data on the disc, which seams to be unreadable by normal pc, but it isnt really. I've read several tries where people tried to read data of the hdd-recorders hdd and couldn't read it. Maybe this can set people in the right direction, as I think more brands use this method...

The page is offline.... It told the story of the hard disc being fat 32 where the bytes were twisted per two bytes, this can be seen with a hex editor browsing the drive. In linux it was possible to read this. He shows that the drive is filled with numbered files where the information is stored, and you needed to create more of the numbered files to use a bigger hard drive.
I hope someone is able to use this info at other recorders to show they use the same system. As I am waiting to buy one until I know it is possible to upgrade the disc.