An image display system includes a host system for executing an application program, a display connected to this host system, and an interface for connecting the host system to the display and used to display an image on the display. This interface enables packetized data including ID information to be transferred from the host system to the display. The interface is composed of a first interface for transferring packetized data together with packet order information and a second interface for enabling less data than the capacity of the first interface to be transferred from the display to the host system together with information of a packet transfer error recognized according to the order information.