Evolution of OS is divided in 5 phases:
Phase 0: (1940-1955):
- Computers are exotic experimental equipment.
- Program in machine language.
- Use plug boards to direct computer.
- No overlap between computation, I/O, think time, and response time.
- Programs manually loaded via card decks.
Phase 1: (1955-1970):
- User at console: one user at a time
- OS becomes a batch monitor.
- OS were written in Assembly languae.
- No structured programming.
- More efficient use of hardware.
- No protection
- Difficult to debug
Phase 2: (1970-1980):
- Interactive timesharing.
- One of the first timesharing systems.
- To let multiple users interact with the system at the same time.
- Users do debugging, editing, and email online.
- More than one user executes their tasks simultaneously.
Phase 3: (1980-1990):
- Created MS- DOS.
- GUI operating systems was developed first time.
- Microsoft Windows: Win 1.0 (1985) .
- Phase 4 (1990-2000):
- Networked Systems: (LAN).
- Different machines share resources, printers, File Servers, Web Servers.
- Internet service providers (service between OS and apps).
Phase 4: (2000-present):
- Mobile and computer operating systems have been developed in different ways and for different uses.
- Computer OS products are older and more familiar to larger groups of users.
- Through this time, Microsoft Windows and Apple’s Mac OS have emerged as the two dominant operating system designs.
- So many types of GUI operating systems are develop in phase 5 major types are: OS system of mobiles. window 95, window 98, window XP, window crystal vista window 8, window 10.
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