Hello, decided to play about with my old 520 last week, and I put a hard drive in it.
I soldered an few arrays of tiny-tiny resistors in it and used an old connector and it sort of works
I had to recompile the kernel using the OLD source code, which is missing a lot. But please bear in mind only the Hard Drive and the Ethernet Port work! (not even the leds light up), this really is not useful, but I thought I'll post it here in case someone might play about with it. Maybe in the future I'll put more effort into it (but I have a lot to learn)
http://speedy.sh/9Njqh/DSM520-Firmware-Bodge.zip(password=forthedlinkforum)
http://i45.tinypic.com/15qtggn.jpgMatt