History of operating systems

History of Operating Systems.

The earliest computers were mainframes that lacked any form of operating system. . Each user had sole use of the machine for a scheduled period of time and would arrive at the computer with program and data, often on punched paper cards and magnetic or paper tape. The program would be loaded into the machine, and the machine would be set to work until the program completed or crashed. Programs could generally be debugged via a control panel using toggle switches and panel lights. Symbolic languages, assemblers, and compilers were developed for programmers to translate symbolic program-code into machine code that previously would have been hand-encoded. Later machines came with libraries of support code on punched cards or magnetic tape, which would be linked to the user's program to assist in operations such as input and output. This was the genesis of the modern-day operating system.

The true descendant of the early operating systems is what is now called the "kernel”

The first operating system used for real work was GM-NAA I/O, produced in 1956 by General Motors Research division for its IBM 704. The main function of GM-NAA I/O was to automatically execute a new program once the one that was being executed had finished (batch processing). It was formed of shared routines to the programs that provided common access to the input/output devices. Some version of the system was used in about forty 704 installations. Control Data Corporation developed the SCOPE operating system in the 1960s, for batch processing and later developed the MACE operating system for time sharing, which was the basis for the later Kronos. In cooperation with the University of Minnesota, the Kronos and later the NOS operating systems were developed during the 1970s, which supported simultaneous batch and timesharing use. Like many commercial timesharing systems, its interface was an extension of the DTSS time sharing system, one of the pioneering efforts in timesharing and programming languages. In the 1970s, UNIVAC produced the Real-Time Basic (RTB) system to support large-scale time sharing.