1. OPERATING SYSTEMS DESIGN AND IMPLEMENTATION Third Edition ANDREW S. TANENBAUM ALBERT S. WOODHULL Yan hao (Wilson) Wu wwu@uwc.ac.za University of the Western Cape Computer Science Department

2. Study Goals Introduce the basic concepts, structure and running environment of the operating system Introduce the principle of the operating system, type of the operation system and its implementation Introduce the history of the operation system and the future tendency Introduce and analysis the typical operating systems Help students to develop the capability of analyzing and solving problems regarding the operating system (Pop quizzes)

3. The Modern Computer System Figure 1.1 A computer system consists of hardware, system programs, and application programs. Microprogram

4. What Is an Operating System? The operating system has two basic functions It is an extended machine or virtual machine Easier to program than the underlying hardware It is a resource manager Shares resources in time and space

5. Operating System Generations Generation 1 (1945 – 55) Vacuum tubes and plugboards Generation 2 (1955 – 65) Transistors and batch systems Generation 3 (1965 – 80) ICs and multiprogramming Generation 4 (1980 – Present) Personal computers

6. ENIAC In 1946, John Mauchly and J Presper Eckert developed the ENIAC. At 27 tonnes and the size of an entire room, the world's first computer is just as elaborate as its name suggests — ENIAC or Electronic Numerator Integrator Analyser and Computer. True to form, ENIAC also makes big noises, cracking and buzzing while performing an equation of 5,000 additions. Before the invention of ENIAC, it took a room full of people to calculate a similar equation http://archives.cbc.ca/IDC-1-75-710-4182/science_technology/computers/clip1

7. Simple Batch System (1) Figure 1-2. An early batch system. (a) Programmers bring cards to 1401. (b)1401 reads batch of jobs onto tape.

8. Simple Batch System (2) Figure 1-2. An early batch system. (c) Operator carries input tape to 7094. (d) 7094 does computing.

9. Simple Batch System (3) Figure 1-2. An early batch system. (e) Operator carries output tape to 1401. (f) 1401 prints output.

10. Control Card Figure 1-3. Structure of a typical FMS job.

11. Multiprogrammed Batch Systems User application Monitor program I/O device User application a User application b Scheduling program I/O device I/O Interrupt I/O

12. Multiprogrammed Batch Systems Several jobs are kept in main memory at the same time, and the CPU is multiplexed among them.

13. Time-Sharing Systems–Interactive Computing On-line communication between the user and the system is provided; when the operating system finishes the execution of one command, it seeks the next “control statement” not from a card reader, but rather from the user’s keyboard. Feature: Multi-user, Interactive Independent In – time service.

14. Real-Time Systems Often used as a control device in a dedicated application such as controlling scientific experiments, medical imaging systems, industrial control systems, and some display systems. Well-defined fixed-time constraints. Hard real-time system. (Time deadline must be meet) Soft real-time system

15. Install MINIX

16. Web Site www.cs.uwc.ac.za/~wwu www.cs.uwc.ac.za/~lyee

17. Control Cards Problems 1.How does the monitor know about the nature of the job (e.g., Fortran versus Assembly) or which program to execute? 2.How does the monitor distinguish (a) job from job? (b) data from program? Solution Introduce control cards

18. Control Cards (Cont.) Special cards that tell the resident monitor which programs to run $JOB $FTN $RUN $DATA $END Special characters distinguish control cards from data or program cards: $ in column 1 // in column 1 and 2 709 in column1

19. Control Cards (Cont.) Parts of resident monitor Control card interpreter – responsible for reading and carrying out instructions on the cards. Loader – loads systems programs and applications programs into memory. Device drivers – know special characteristics and properties for each of the system’s I/O devices. Problem: Slow Performance – I/O and CPU could not overlap ; card reader very slow. Solution: Off-line operation – speed up computation by loading jobs into memory from tapes and card reading and line printing done off-line.