Originally Posted by jpierce237
Also, I wonder if it might not be possible to prepare a standard external drive for use via ESATA in place of the now defunct WD DVR Expander?
While that can be done, and outfits like Weaknees (and perhaps others) are doing it commercially, it's not so easy. The allowable external drives are hard coded into the TiVo software, and so byte-level modifications would have to be made to the code on the current hard drive.
And even then, it would be difficult to modify the code for any model drive except the specific one you wished to install.
I haven't looked at this for a while, and so things may have changed, but that's how it was with every TiVo that didn't support the old Kickstart mode of adding an external drive (all the ones after the S3 OLED, I believe). I'm sure someone will speak up if I'm wrong (which would not be too unusual).