To display the program of a digital TV broadcast with high image quality on a computer after satisfying a copyright protection rule.

The digital TV broadcast viewing system comprises a tuner board which has a tuning means, an extending means and a terminal for outputting non-compression digital program image data, which is obtained from the extending means, and which is mounted on the extension slot of a PCI bus; a graphic board which is mounted on the extension slot of an AGP bus and which has an input terminal for the program image data, a means for converting the digital type image data into prescribed standard digital display data, and a terminal for externally outputting the digital display data; a cable for connecting the input/output terminals of the program image data; and a control means for controlling the tuner board via the PCI bus and the graphic board via the AGP bus, so as to conduct a tuning control processing, a program image data output control processing, a frame image generating processing, an image synthesis control processing and an image output control processing.