Abstract: A communication control method for use in a communication system including a plurality of communication control apparatuses interconnected through an information transmission path, each of the communication control apparatuses including a packet transmission/reception unit, a timer unit and a controller unit. When a first communication control apparatus has become unable to perform communication due to accidental power-off or a power supply failure or the like in the course of communication with a second communication control apparatus (which has been brought into a locked state by the first communication control apparatus), the invention prevents the second communication control apparatus from being left permanently in the locked state.

Abstract: Messages are transmitted via a gateway between terminal equipments in different communication networks. The message includes a source address, a destination address, a first header information set, at least one data block, and an end code. The source address corresponds to the terminal equipment or the gateway from which the message is transmitted. The destination address corresponds to the terminal equipment or the gateway to which the message is directed. The first header information set has routing information related to the terminal equipments between which the messages are transmitted. The data block includes a second header information set and a command. The second header information set has routing information related to sections of the terminal equipments between which the messages are transmitted. The command is given to the section of the terminal equipment to which the message is directed.

Abstract: A data storage apparatus comprises a memory circuit including 2.sup.n1.multidot.n2 memories for storing binary information. Data of N bits from the row direction and column direction can be written and read out in parallel, and, also, such data of N bits reduced with a data reduction rate of an exponential power of 2 can be written and read out in parallel. The apparatus is used, for example, for displaying data on a display by fetching the data from common file servers connected to a private network or the like.