What do you do if your HDTV is so old it does not have HDMI cable input?

As HDTV made its entrance to the market, HDMI was not available. Because of this, there are a handful of HD televisions that have only analog HD inputs or perhaps RGB inputs.
HDMI was introduced by the television industry as a small and convenient connector for video, audio and control lines between a source and display. The interface is fully digital and happens to support an encryption system that prevents the signal being accessed for unauthorized recording and distribution. Unlike all other video interfaces, HDMI connectors are used under a commercial licence that restricts the use of them. One of the effective prohibitions is to use the connector in a device that decodes encrypted material to any un-encrypted signal such as analog HD links.
For the unfortunate few that have HD televisions without HDMI ports, it is unlikely that there will be a method of watching commercial HD content. It is certainly worth contacting the manufacturer to see if they are able to offer upgrades that may solve the problem. OR if the TV has 'component' inputs, use them and the picture will look great, if that doesn't work, use the S-connector. You will still have use audio cables.