| 摘要 |
PURPOSE:To ensure the effective use of a channel command CC word area by adding a CC word controller which deletes a chain via a channel command controller even though a command-chained channel command is issued from an input/output controller. CONSTITUTION:When an input/output control processing program 2 performs plural input/output operations to an input/output controller 4, the controller 4 sets a command-chained channel command word CCW at a CCW area 3 of a CCW controller 7. Then the command chain of the CCW is deleted out of the processing of a CCW control program 8. The program 8 produces an input/output start instruction to the controller 4. Thus the controller 4 is started to receive a CCW free from the command chain and performs a series of processes to the CCW. Then the controller 7 outputs a process end interruption to the program 2. |
