A majority of the operating systems today for both servers and mainframes trace back to third-generation computer systems. Such significant concepts as multiprogramming, sequential process, virtual memory, hierarchical file systems, and timesharing were introduced by these systems. Such concepts have been instrumental in enhancing the utilization and throughput of the system. The implementation of various projects during the 1960s helped in not only the testing of novel concepts in the operating system but also in the construction of timesharing systems (Dennig 1971 p. 182). The multiple access system, atlas, and compatible timesharing systems are a few of the operating systems that were developed, at the time. However, one of the projects of the time that eventually proved to be the most ambitious was Multics (Multiplexed Information and Computing Service) that had been developed for General Electric (Organick 1972 p. 7). This operating system embraces each and every significant system concept, at the time, such as inter-process communication, processes, page replacement, segmented virtual memory, protection rings, access control, and device independence, amongst others. About the same time, UNIX was developed as an operating system, to replace the hierarchical file system (Ritchie & Thompson 1974 p. 369). Its design was with a view to complementing DEC PDP computers, and it distilled some of the most valuable features that the Multics operating system had into a kernel that could be incorporated into a minicomputer’s small memory.
During the 1980s, new forms of operating systems that were meant to serve personal computers were developed, and these include PC-DOS, MS-DOS, Coherent, Apple-DOS, CP/N, and Xenin (Denning 1976 p. 362). One of the disadvantages of all these systems is that their functionality was quite limited, seeing that they had been initially designed to work with microprocessor chips of between 8 and 16-bit memory. These operating systems were then phased out by the development of other operating systems that were meant to work with Multiprocessors, and these include OS/2 and Windows NT.
As more advanced operating systems were being developed, the processing speed and the memory of the microprocessor were also increasing. When computer networks and multiprocessors were being improved during the early 1980s, operating systems found another use of managing simultaneously managing multiple computing resources. A good example, in this case, would be Star OS. At the same time operating systems that initially worked on a single machine (for example, Unix), were also being developed to take into account computer networks. The personal-computer OS had already been merged with the functions of the mainframe, during the later years of the 1990s. During this time, a majority of the organizations were realizing that the system administrator of distributed systems was extremely high, and hence there is a need to have central and simplified management for large computer networks. Consequently, Solaris, the server operating system for Sun Microsystems, was developed. Other types of operating systems that were also developed include Linux operating system which is free, and Microsoft’s NT (Denning, Hunt & Tichy 1999 p. 3). Today, it is important that operating systems are able to support fast communication and synchronization. Accordingly, each processor requires individual devices attached to it, with the result that an operating system ends up controlling a host of Input/Output channels simultaneously.
Dennig, P. J. (1971). “Third generating computer systems”. Computing surveys, Vol. 3, No. 4, pp. 175-212.
Denning, P. J. (1976). “Fault-tolerant operating systems”. Computing surveys, Vol. 8, No. 4, pp. 359-389.
Denning, P. J, Hunt, J. J, & Tichy, W. F. (1999). Operating systems. Web.
Organick, E. L., 1972, The Multics system: an examination of its structure. Cambridge, Mass: The MIT Press.
Ritchie, D. M. and Thompson, K. L. (1974). “The UNIX time-sharing system.” Communications of the ACM, Vol. 17, No. 7, pp. 365-375.