The present game machine system allows a user to enjoy, at home, games according to supplied game software at low cost. The game machine system includes a game machine, an STB, and a television receiver, which are connected to each other via a digital bus that is external to them all. The STB receives game software transmitted via digital broadcasting and stores the received game software on a hard disk in the STB. The game machine executes a game while accessing the hard disk to read the game software as required. An image generated by the game machine and image data such as a background image output from the STB are supplied to the television receiver via the digital bus and a game image is displayed on the screen of the television receiver.