英语翻译计算机高手帮下啊,希望是手动翻译不是机器翻译,感激不尽.Off-the-shelf operating syst

Off-the-shelf operating systems for embedded systems began to appear in the late 1970s.Many of these were written in assembly language,and could be used only on the microprocessor for which they were written.When microprocessor became obsolete,so did its operating system,unless it was rewritten to run on a newer microprocessor.When the C language came along,operating systems could be written in an efficient,stable and portable manner.This had instant appeal to management,because it held the hope of preserving the software investment when the current microprocessor became obsolete.This sounded like a good story in a marketing pitch.Operating systems written in C became the norm and remain so today.In general,reusability of software has taken hold and is doing rather nicely.A number of commercial operating systems for embedded systems sprang to life in the 1980s.
二十世纪七十年代后期,应用于嵌入式系统的通用操作系统开始出现.它们很多是用汇编语言写出来的,只能用在编写了它们的微处理器上.随着微处理器逐渐过时,这种操作系统似乎也难逃被淘汰的命运,除非它被重新编写,以便在新一代的微处理器上运行.当C语言出现时,操作系统已可以用高效、稳定、便携的方式来编写了.这一优势颇受管理层的青睐,因为他们看到了在当下微处理器被淘汰时保全软件投资的希望.在市场方面,这同样是个传奇故事.用C语言编写的操作系统成了一种标准,至今依然如此.总地来说,软件的可再用性已深入人心,目前表现仍令人满意.在八十年代,一大批的嵌入式商业操作系统获得了新生.