Like any computer, a TiVo set uses an operating system (OS) to manage the set's resources and applications. TiVo's OS is based on Linux, and the modifications to the Linux kernel operating system are available to the general public on request. Enterprising programmers have studied the TiVo OS to not only learn how it works, but also to make modifications. Of course, doing so usually violates the TiVo warranty and might even lead to the discontinuation of the owner's service.
TiVo's DVRs are grouped by generations called Series. Series1 DVRs were made by third party manufacturers, including Phillips and Sony. These DVRs were designed to work exclusively with TiVo's services. Series1 DVRs were relatively easy to hack, and there are many Web sites devoted to teaching owners how to modify a TiVo to increase hard drive space or expand functionality. Series1 DVRs required an outside phone line in order to complete a guided setup process. They also lacked the ability to link in to a home network. TiVo has phased out Series1 DVRs, but the TiVo service still supports them.
Beginning with Series2, TiVo began offering its own brand of DVRs. Customers with Series2 sets can integrate their TiVo into their home network, opening up a host of new options. The Series2 Dual Tuner model allows users to record two programs at the same time while watching a third pre-recorded program. HUMAX and Sony also manufacture Series2 TiVo sets.
The latest model is the Series3 HD DVR, which can record high definition channels. Like the Series2 Dual Tuner model, the Series3 TiVo can record multiple channels at the same time. You can also hook it into your home network, though not all the cool features you get with a Series2 TiVo are supported yet. TiVo says that users will be able to download software to their Series3 TiVo sets as new applications are supported.
In addition to the three Series, some manufacturers offer DVD recorders that have a hard drive and are programmed to work with TiVo. HUMAX, Pioneer and Toshiba all offer such models. With these sets you can burn pre-recorded programs to DVD using one unit.
No matter which generation of TiVo you own, some common rules apply. The capacity of your TiVo is determined by the size of the hard drive in the unit and the quality setting you choose for recordings. TiVos have four levels of recording quality: Basic, Medium, High and Best. Lower settings are highly compressed and take up less space on the hard drive but may be choppy or blocky when played back. Some TiVo models can record up to 30 hours of programming at the Basic setting, while others can hold up to 300 hours. Higher settings require more hard drive space but playbacks are smoother and clearer.
The lower settings are ideal for programs that don't have a lot of fast-paced action in them, such as a cooking show or the news. Sports events and action-packed programming look better when you use the higher settings. According to TiVo's Web site, a Series3 HD DVR can hold:
- 300 hours of programming at the Basic setting
- 120 hours of programming at the Medium setting
- 76 hours of programming at the High setting
- 52 hours of programming at the Best setting
- 32 hours of high definition programming
Once the system reaches capacity, it will search for old programs to delete in order to make room for new selections. The service prioritizes programs for deletion. The first programs listed for deletion are TiVo Suggestions (we'll talk about those later). After that, TiVo begins to delete the oldest programs.
TiVo sets can cost anywhere from $90 to $800, depending on which set you want. TiVo may even offer a particular set for free when you sign up for your TiVo service. Prices and offers vary throughout the year, so it's important to check TiVo's Web site to see what your options are.
In the next section, we'll look at TiVo's subscription service.