The I/O operation mode of a computer system. Programs requiring a significant amount of communication with “slow” peripheral devices may have their data routed at highspeed transfer rates to the disk for later rerouting to the intended devices. The result is that tasks are completed faster, thus freeing main memory so other tasks may be executed. It also allows automatic storage of data on the disk if the intended device is nonoperational. In addition to output spooling, input spooling is available. This permits jobs and data entered through “slow” devices to be routed to the disk. When the spooled jobs are to be executed or when the spooled data is required, the executive program loads them from the disk into main memory.; 計(jì)算機(jī)系統(tǒng)輸入輸出的操作方式。需要與慢速外部設(shè)備進(jìn)行大量通信的程序先以高速將 數(shù)據(jù)送給磁盤,然后在適當(dāng)?shù)臅r(shí)候再把數(shù)據(jù)從磁盤送給慢速外部設(shè)備。其結(jié)果是任務(wù)完成得 較快,并能及時(shí)地空出主存使其它任務(wù)得以執(zhí)行。即使想用的外部設(shè)備當(dāng)時(shí)并沒有工作,也同 樣先將數(shù)據(jù)自動(dòng)地存入磁盤。除了輸出假脫機(jī)之外還有輸入假脫機(jī),它讓作業(yè)和數(shù)據(jù)由慢速 外部設(shè)備送入磁盤,當(dāng)執(zhí)行假脫機(jī)作業(yè)或需要用假脫機(jī)數(shù)據(jù)時(shí),再由磁盤讀入主存。