1. 240-323 OS part I, 2000 1 240-323, Part I Computer System Structures Department of Computer Engineering, PSUWannarat Suntiamorntut

2. 240-323 OS part I, 2000 2 Department of Computer Engineering, PSUWannarat Suntiamorntut Computer - System Operating

3. 240-323 OS part I, 2000 3 Department of Computer Engineering, PSUWannarat Suntiamorntut Computer - System Operating Steps Have an initial program to run (Bootstrap program) Boot Init Wait Ready interrupt

4. 240-323 OS part I, 2000 4 Department of Computer Engineering, PSUWannarat Suntiamorntut Computer - System Operating Table of pointers is stored in low memory are need. These locations hold address of the interrupt service routines. (interrupt vector) The process when interrupt occur - return address was kept. - other interrupts are disabled.

5. 240-323 OS part I, 2000 5 Department of Computer Engineering, PSUWannarat Suntiamorntut I/O Systems

6. 240-323 OS part I, 2000 6 Department of Computer Engineering, PSUWannarat Suntiamorntut Different requirements lead to multiple buses Processor bus (on chip) - > 1 GB/sec Memory bus (on processor board) - ~500 Mbytes/sec I/O Bus ~ 100 Mbytes/sec Device Bus (SCSI) (Small Computer System Interface) - ~ 10 Mbytes/sec

7. 240-323 OS part I, 2000 7 Department of Computer Engineering, PSUWannarat Suntiamorntut Disks

8. 240-323 OS part I, 2000 8 Department of Computer Engineering, PSUWannarat Suntiamorntut I/O Interface

9. 240-323 OS part I, 2000 9 Department of Computer Engineering, PSUWannarat Suntiamorntut I/O Interrupts

10. 240-323 OS part I, 2000 10 Department of Computer Engineering, PSUWannarat Suntiamorntut I/O Operations

11. 240-323 OS part I, 2000 11 Department of Computer Engineering, PSUWannarat Suntiamorntut Hardware Protection

12. 240-323 OS part I, 2000 12 Department of Computer Engineering, PSUWannarat Suntiamorntut System Calls or Monitor Call