A composition comprising a supported hydrogenation catalyst comprising palladium and an organophosphorous compound, the supported hydrogenation catalyst being capable of selectively hydrogenating highly unsaturated hydrocarbons to unsaturated hydrocarbons. The method includes: sending a request to a peripheral in a performance of a task; determining that a peripheral bus timeout occurred; sending an interrupt signal; retrying for an access to the peripheral; completing the request if the retry for the access to the peripheral is successful; and resuming the performance of the task. A circumferential velocity of each image supporting member is determined so as to be higher than a circulation velocity of the belt member. If no further increase of clock frequency of the clock signal is possible, a charge pump is connected for an EPROM in order to increase the writing speed thereof.