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Historical analysis of UNIX development
After more than 30 years of use, Bell Labs UNIX computer operating system is still considered as one of the most powerful and flexible operating systems in the computer world. Its popularity is due to many things. One of them is the ability to run a variety of machines, from single-user workstations to supercomputers. UNIX's portability also makes it adopted by many manufacturers. The system also puts forward a unique software design method, which solves problems by connecting simpler tools with each other instead of creating large-scale applications.
Its development and evolution led to a new computational philosophy. In the early days of computing, computer systems did not communicate with each other. Even various computers produced by the same company often need translation. Forget the interoperability of systems from different vendors. Most operating systems can usually only perform a limited number of tasks, and they can only be executed on machines written for them. If an enterprise upgrades to a larger and more powerful computer, the old operating system usually cannot run on the new computer, and usually the company's data must be input into the new computer again.
Try to develop a convenient, interactive and usable computer system that can support many users. At 1965, a group of computer scientists from Bell Laboratories and General Electric Company joined MIT's ongoing work called multiplexing information and computing service host time-sharing system. The project failed because the team's efforts failed to produce an economically useful system at first. Bell Laboratories withdrew from this work on 1969. Ken Thompson, dennis ritchie, Doug mcilroy and J.F. Osana, four people from Bell Laboratories Computing Science Research Center, continued to work on this project and eventually created the UNIX operating system.
The first version of UNIX was written in assembly language, but Thompson's intention was to write in a high-level language. Thompson first tried FORTRAN at 197 1, but gave up after the first day. Then, he wrote a very simple language, which he called B. It worked, but there were some problems. Because implementation is interpreted, it is always slow. Ritchie added a type to B, which was once called NB, meaning "new B", and then he began to write a compiler for it. The first stage of C is actually the two stages of B and NB. The second stage is to rewrite UNIX with C.
Thompson started in the summer of 1972, but there were two problems. Find out how to run basic collaborative programs and how to transfer control from one process switch to another. The second problem is that it is difficult to get the correct data structure because the original version of C has no structure. Together, these things made Thompson give up all summer In the following year, Ritchie added the structure, and in the following summer, they worked together in Qi Xin to redo the whole operating system in C language.
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