Various instructions ( such as i / o instructions and halt instruction ) are privileged and can only be executed in monitor mode 許多的指令(如i / o指令,停止指令)為特許指令且僅僅能夠在監(jiān)控模式下運(yùn)行。
Once these changes ( dual mode , privileged instructions , memory protection , timer interrupt ) have been made to the basic computer architecture , it is possible to write a correct operating system 一旦對(duì)一個(gè)基本的計(jì)算機(jī)體系結(jié)構(gòu)完成了以上修改(雙模式、特許指令、內(nèi)存保護(hù)、定時(shí)器中斷) ,就有可能寫出正確的操作系統(tǒng)。