Last night, I hacked the Tivo and lived to tell about it. The Tivo HD comes with a 160GB drive which is good for 20 hours of high def recording (184 standard def hours.) That's quite a bit, but on busy sports weekends, 20 hours fills up pretty quickly. Plus, this is supposed to be a pretty easy hack and I wanted to give it a shot.
I ordered a 500GB Western Digital hard drive from NewEgg along with an external SATA USB drive enclosure. Once I had the material, it was pretty straightforward. I opened up the Tivo and took out the hard drive (make sure you have a Torx wrenches!) I connected the 500GB drive to my system via the USB enclosure and connected the Tivo drive to a SATA connection inside my computer. I fired up WinMFS and ran mfscopy. I goofed a little and forgot to delete all the old TV shows from the Tivo so the mfscopy command took the time to copy over all those recorded shows. It took about an hour, but it would have gone much faster if I had remembered to delete the shows first.
After mfscopy finished, I made a backup of the original Tivo drive (something I should have done at the beginning.) I'll keep the Tivo drive untouched for a while to make sure the new one is ok, but if it works then I'll wipe the old Tivo drive and use it for regular storage. Theoretically I can restore that backup at any time.
The mfscopy is supposed to copy over all the Season Passes, Cable Card settings, etc. It's a bit for bit copy of the whole drive. I really didn't want to go through the Cable Card pairing again so I was hoping that it really did work. I put the 500GB drive into the Tivo and fired it up. It worked perfectly! My Tivo now says that I have 64 hours of HD space and 607 hours of standard def space. It's going to be hard to fill that up unless I leave the house for a month.
There are some firmware changes you can make to hard drives to make them run slower and be a bit quieter. I didn't do any of those and it turned out ok. I do hear the hard drive a little, but that doesn't bother me. If you're really concerned about the noise, find that tool and/or pay a little extra for one of the Seagate DB35 drives. TivoCommunity.com has all the info you need.
All in all this was a very simple "hack." After Tim saw how it worked he said, "That's not even a hack." He's right. It's really simple as long as you're willing to void your warranty and risk destroying your investment. Beyond that you only have to click a few buttons and wait. Go for it!