Abstract: A failure detection method enabling the detection of I/O bus failure and address parity error when installing I/O controllers connected to a system bus in a computer system, and also enabling failure location when installing units in slave/master relationships (e.g. SCSI controller and disk storage units) and when installing an additional slave in a computer system, thus improving the reliability of the system. The failure detection method comprises the steps of executing an instruction which involves providing I/O bus access to a memory to be used by an I/O controller after installed, determining that there is no failure when predetermined results are obtained with the instruction, and installing the I/O controller in the system.

Abstract: A failure detection method enabling the detection of I/O bus failure and address parity error when installing I/O controllers connected to a system bus in a computer system, and also enabling failure location when installing units in slave/master relationships (e.g. SCSI controller and disk storage units) and when installing an additional slave in a computer system, thus improving the reliability of the system. The failure detection method comprises the steps of executing an instruction which involves providing I/O bus access to a memory to be used by an I/O controller after installed, determining that there is no failure when predetermined results are obtained with the instruction, and installing the I/O controller in the system.

Abstract: This agent purchase method for agent purchase via communication lines comprises a step which, by receiving from the user terminal the specification of the purchased merchandise and the specification of the seller selling the merchandise via communication lines as the supplier of the merchandise, accepts the request for agent purchase of the merchandise, a step to refer to or update the credit level record of the seller for transactions, a step to purchase the merchandise requested for agent purchase from the seller and deliver that merchandise to the user and a step to manage charging for the agent purchase service provided to the user.