I don't recommend anyone do this unless they own their HR20 and understand that you are on your own as far as D* is concerned so don't call them if you have issues or break your box, you are pretty much toast. This was intended as a proof of concept for an upgraded hard drive, not intended to be a guide or procedure to do so. I figured since the SATA port is disabled for the external port, and I had a HR20 that hadn't been activated yet I'd see if I could upgrade the HD. I opened up the box, unplugged the SATA cable from the internal HD controller and active onboard controller, and plugged in the external SATA cable to controller 1. I then plugged in my external SATA HD, which I had hoped would just work out of the box, with the external port, powered up and waited. Soon enough, it booted up, I went through the setup menu, activated the device and all is well: External 300GB SATA HD running off controller 1, internal HD disconnected. I have HD programs recording for the next 24 hours on both tuners now to the external SATA HD. I also have an internal 500GB HD SATA drive on hand which I plan to likely take back and replace with a 750GB SATA drive, as it seems that in all likelihood it should work. What I don't know: -If I can take the external SATA drive and plug it into my other HR20, reverse the controller cable, reboot and see the recorded program I have on the drive. (This would allow Sneaker Net for MRV until it becomes available) -If it requires an unactivated or formated HD to work the first time -What will happen if I plug the external sata cable back to controller 2 and reboot. -What will happen if I plug both internal and external sata cables back into the controllers and attach both external and internal drives and reboot. -If I can use all the space on the HD (300, 500, or 750GB SATA) -What happens when I reboot the HR20 without the HD attached or powered on -What happens when I plug the orginal HD back in and reboot. Interestingly enough, I have not received even the initial software update, I am guessing because I am actively recording on both streams. I also noticed the sound effects option was not grayed out, so I was able to tab to it, these are the settings for screen navigation volume level. Needless to say, there is no menu sound even though it's accessible, likely why it was grayed out with the initial update. I am going to wait till I get some more recorded material on these devices and test some of these scenarios out. Now if D* had just released the box with the external sata port enabled I wouldn't be tinkering. In all likelihood D* is going to enable the external port for expanded space, so my efforts are just to find out if it can be done. All this is pretty interesting to me and likely explains why the box is so quick, it appears recorded programming is all that's stored on the HD, which is good and bad if this turns out to be true.