There used to be a thread or threads with info about connecting a external hard drive to the Scientific Atlanta 8300 HD DVR. These threads went back a couple of years and now they are gone. I did a search and nothing. There used to even be a sticky for it.
I can't imagine that discussion about doing so wasn't allowed since cable co's allow it since there is no theft of services and the external HD once connected only works with the DVR it is connected to for replay.