Digital video recorders allow users to record movies and TV shows from a cable or satellite TV source without the need for VHS tapes, DVDs or other physical media. Cable companies, such as Comcast, often use DVRs as a way to add value to subscription packages, providing subscribers with a company-branded DVR unit for little or no additional charge. Some of these DVR units have USB ports on them which have no apparent function.
Comcast DVR
DVR units provided by Comcast to individual customers may be one of several different DVR models created by different manufacturers. Though they offer the same core function, the physical layout of the units may differ. Some DVR units have a single USB port on the front and one or more additional ports on the back of the unit, while others feature only a single USB port. The physical layout of a DVR unit does not affect the end user experience, however.
Disabled Ports
The USB ports on DVR units supplied by Comcast are disabled by default. This is intended to prevent the removal of data from the DVR unit as well as the addition of data or programs to the DVR. This ensures that users cannot record programming and transfer it to other digital media and also protects the DVR unit from unauthorized firmware upgrades or other software modifications that could cause it to function in ways other than those which Comcast intended.
Purpose of USB Ports
Some users may wonder why the USB ports are added to DVR units if they are not enabled. The reason for this is that the DVR models used by Comcast are available for use by other service providers and individual consumers who may wish to use the units with the USB ports enabled. An active USB port on one of these DVR units can be used to adjust settings on the unit, upgrade the software that the DVR unit uses, to add peripherals such as a keyboard to the unit or to add additional storage space to the unit via an external hard drive.
Recording from DVRs
Though the USB ports on Comcast DVRs are disabled, it is still possible to record video onto DVD from one of these DVR units. Connecting the unit to a computer's TV tuner card via HDMI or other connection types allows the user to capture video data in real time as it plays on the DVR. Comcast DVR units produced by Motorola offer additional options as well as they feature Firewire ports on the back panel of the unit; connecting the DVR to a computer via Firewire and installing software drivers for the Motorola DVR's Firewire connection.