Can I upgrade the 80GB hard disk to a larger size?
Probably not unless you have a Digicrystal 9000 from December-2005 or earlier which allows unofficial firmware to be loaded or you’ve upgraded to the 23-02-2006 firmware. If you want to try follow the instructions at http://users.bigpond.net.au/PCPro/firmwareflash.htm after installing the official 23-02-2006 firmware.