PURPOSE: To use shared terminal equipment as one system by eliminating the mixture of control code sequence in the shared terminal equipment.

CONSTITUTION: This system is comprised in such a manner that a terminal connection device 6 provided with control buffers 8, 9 to store the control code sequence of each system is provided between an operating system 1 and a standby system 2 and the shared terminal equipment in a hot standby system in which the shared terminal equipment 7 is shared with the operating system and the standby system, and untransmitted control code sequence in the control buffer in accordance with the operating system is found out when a switching request is received from the standby system by the terminal connection device 6, and after it is transmitted to the shared terminal equipment, the shared terminal equipment is connected to the standby system.