| 摘要 |
PURPOSE:To show the capacity of an external storage controller/channel at its maximum and to ensure an effective countermeasure to a fault, by enabling the transfer of data by switching the external storage device to an optional external storage controller during a series of operation controls. CONSTITUTION:Plural magnetic disk controllers DKC2 are connected to the channels which are connected to a CPU. The connecting switches 5 are connected to the controllers DKC2 via connecting signal lines 3. Then magnetic disk control memories 6 are connected to the controllers DKC2 via the changeover switches 5. The magnetic disk storage devices DKU-1-DKU-n to the memories 6. The presence/absence STFM for command which sets the channel No. CHNO, the DKC No. DKCNO and the FM, the SEEK showing the cut-off state, the ADDRESS, SET, SECTORNO, etc. are stored in the memories 6. Then the devices DKU-1-DKU-n are switched optionally during a series of working controls. Thus the channel capacity is shown at its maximum via the memory 6 to ensure an effective countermeasure to a fault. |
