I can tell you a very safe way to find out ... and this shouldn't ruin the unit in the process...
you need:
-a larger hard drive
-your computer
-The following trial version of this drive image program
http://www.drive-image.com/Drive_Image_Download.shtml
To try it ...
1.insert the new hard drive in your computer
2.insert the dvd recorders hard drive in the computer
3. format the new hard drive
4. run the drive-image program and copy the dvd recorder drive to the new hard drive
5. put new hard drive in the recorder
not sure if it works but that is how you could do it. The BIOS on the recorder may not allow a larger size disk and may only read 80G off of whatever size disc you use.
Jason
January 2008