Rather than order a connector he pulled the circuit board out of an old USB hard drive enclosure and connected to his DVD drive. Bang, recognized and running.

Besides the hard drive, you’ll need a docking station, mounting enclosure, or adapter to connect the HDD to your PC. For a barebones setup ...

Unboxing and giving a brief overview of the Hornettek Goliath USB 3.0 Hard Drive Enclosure. More information at <a href="http://www.ThinkComputers.org">http://www ...

Suitable for 2.5” SATA/SSD;Supports Standard Notebook 2.5″ SATA and SATA II Hard drives Optimized for SSD, Supports UASP SATA III,Backwards-Compatible with USB 2.0 or 1.1 Hot-swappable ...

The enclosure that he’s using is meant for a 5.25″ optical drive. It comes with a USB to SATA converter which is how he connects the hard drive to the Raspberry Pi serving the files.