6.To performanoperation at the same time that another operation is being performed; for example, to perform input/output operations while instructions are being executed by the processing unit.
8.A condition in which the central processor of a computer attempts to performan illegal or forbidden operation or in which it is continuously repeating the same routine.
10.A directive(by means of a basic transmission unit) from an access method that causes the network control program to perform a data-transfer operation or auxiliary operation.