I cut the cable a few months ago and that has worked out well.  PrismTV 
from CenturyLink was pricey and I hardly used it.  They told me I don't 
need to return the box, but it has this little hard drive inside:

https://www.amazon.com/Toshiba-2-5-inch-laptop-5400rpm-MQ01ABD050V/dp/B0100ZM5QG

It was pretty easy to access it -- a door on the back says "HDD" on it and 
it just takes a little hex screwdriver to open it (and then pry it off 
with a knife).

I'm going to add it to one of my linux boxes to see what it has on it. 
It should have a bunch of TV shows, but I assume they are encrypted 
somehow.

Have any of you played around with one of these drives?  I wonder if there 
is anything recoverable and of interest.  Also, I wonder what filesystem 
they use and how big the files are.  I'll let you know what I find out.

Mike