1. Operating Systems University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Dr. E.C. Kulasekere

2. What's Next? University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Assembled computer available. Choice of right tool to integrate. Should we use a screwdriver to pound nails into the wall? Any guidelines to choose the right tool?

3. Operating System Selection University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Single or Multiple OSs? Type of OS; Microsoft-style or Unix- style? Matching the OS to your ability, application software need and urgency of use.

4. Multi-OS System University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Leave plenty of space. Consider running an Emulator. Setup data exchange between OSs. Investigate Hardware needs. Drivers available for current hardware?

5. Hardware Compatibility Issues University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 The Motherboard. I/O and peripheral cards. The CPU and its performance. Memory capacity adequate? Mass storage devices. Multimedia compatibility.

6. Expectations From a New OS University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Give yourself adequate time. Research what problems need to be solved. –Software based. –Stability of OS. –Curiosity Expect a learning curve.

7. OS Installation Basics University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Disk Partitioning. –Shared partition? –In separate partitions? Partition types. –Primary partitions –Extended partitions. –Logical partitions

8. OS’s for x86 Hardware University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 DOS variants. Windows 9x. Windows NT/2000. Unix variants. Any advantages of using a particular OS?

9. Windows 9x University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Introduced 32 Bit support. Requires at least a 386 computer. Does preemptive multitasking. VFAT extension with long filenames. FAT32 support. Tighter network integration. Boot into a GUI.

10. When to Move on University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Internal and External security is lax. Multi-user configuration is primitive. Questionable stability. DOS based OS core. Low performance compared to NT and UNIX.

11. Windows NT/2000 University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 32-Bit multitasking kernel. Works on non-Intel platforms. NTFS which is faster and more reliable than FAT is introduced. Improved multi-tasking and networking. User access control.

12. When to Move on University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Imperfect 16-Bit support. NTFS incompatibility with most other OSs. Reduced hardware support (Windows 2000 rectifies this). Concurrent multi-user performance is low.

13. Linux University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Open source and free. Robust multi-tasking environment. Excellent networking capabilities. Customizable X-windows GUI. Excellent, stable multi-user capabilities.

14. When to Move on University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 16, 2002 Steep learning curve. Open source results in network security problems. Limited number of end-user applications. Poor hardware support.

15. The Boot Process University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Multi OSs should be coaxed to boot. BIOS as a boot loader. Methods the boot loaders work in multi OS systems.

16. BIOS History University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 17, 2002 16-Bit and 32-Bit addressing and the BIOS. BIOS interface with low level Hardware. BIOS as a POST and boot handoff. CMOS and PnP uses of BIOS.

17. BIOS Types University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 17, 2002 AMI BIOS, Phoenix BIOS, Award BIOS. Add on BIOS cards. Video BIOS. SCSI BIOS. Sound and Multimedia hardware BIOS.

18. BIOS Updates University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 17, 2002 Rewriting EEPROM or Flash BIOS. Upgrades eliminate bugs. Upgrades add improvements. Process is extremely dangerous. May result in an unbootable system. Sketch of finding and upgrading.

19. BIOS and Hard Disks University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 17, 2002 The connection to OS installation. Motherboard BIOS controls EIDEs. SCSI Hard Disks are controlled by SCSI BIOS. What is CHS disk geometry?

20. The Modern Hard Disk University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly July 17, 2002

21. The Hard Disk University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Rotational speed is important. Head reads typically 512 Bytes at a time. Cylinder, head, sector---CHS BIOS reads the CHS to understand address of boot loader.

22. The 1024 Cylinder Limit University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Result of bit allocation for the CHS geometry in the BIOS. At Boot time only the 1024 cylinders are seen OS loader should be within this limit to load. In olden computers the limit on hard disk capacity is 540 MB.

23. Getting around 1024 limit University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Ignore it. Make sure the boot loader is within the 1024 cylinders. Eg. Linux CHS geometry translation carried out in the hard disk controller. Total drive capacity remains the same. SCSI uses LBA which has one 28-bit sector number.

24. Boot Loader – Single OS University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015

25. Boot Loader – Multi-OS University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015

26. Types of Boot Loaders University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Floppy based. Eg. Linux. Can be used to check a new OS. MBR-Based. Popular but can be destroyed by other OS installation Boot sector- based. Less susceptible to be destructed with new installations.

27. Common Boot-loaders University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 NT-loader. Linux LILO. System commander. Boot magic.

28. Uses of Partitioning University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 TO save space. Eg. FAT16 partition sizes should be less than 511MB. Easier disaster recovery. Location of data can be positioned so that hard drive seek is easier and head wear is minimum.

29. Tools for Partitioning University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 FDISK. For DOS and Linux Windows NT disk administrator PartitionMagic. FIPS.

30. FDISK (DOS) University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Tightly coupled with the partition type. Primary should be created before extended. Unable to create more than one primary. Partition placement is not allowed. The allocation is automatic. Unable to cope with non-FAT partitions.

31. NT Disk Admin University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Graphical user interface. Can create multiple primary partition. Can create a logical partition without a primary partition. Can delete non-FAT partitions.

32. PartitionMagic University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Graphical user interface. Can create multiple primary partition. Can create a logical partition without a primary partition. Can delete non-FAT partitions. Create file system. Moving and resizing partitions. Copying and converting partitions.

33. Partition Formatting University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Low-level:--Erases the data and file system structure. Takes time. Rebuilds the disk structures. High-level:--Basic structure like boot sector and root directory are created. Takes a short time.

34. When to modify and repartition? University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Adding an OS. Deleting an OS. Shifting disk space requirement. Adding a new hard disk.

35. Consequences of Repartitioning University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Drive letter changes: Software becomes unusable. Extreme cases the OS becomes unbootable. UNIX device identifier changes: mount points can change and the OS becoming unbootable. Change /etc/fstab to reflect changes.

36. When to modify and repartition? University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Adding an OS. Deleting an OS. Shifting disk space requirement. Adding a new hard disk.

37. Optimizing Partitions University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Outer most part of a disk platter is faster than the inner most platter in a hard disk. Applications that need best performance should be placed first. Eg. Swap space, most frequently used programs, large data files.

38. Dangers of Too Many Partitions University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Increased head movement can damage hard disk

39. Installing the OS University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 Microsoft OSs copy the installation files to hard disk for optimal performance. For UNIX OSs choose the partitions appropriately so that disaster recovery can be easier. Choose appropriate code changes. Position the /boot below 1024 cylinders or use a floppy. Install MS OS before anything else since it damages other OSs.

40. Installation Problems University of Moratuwa Department of Electronic and Telecommunication Engineering Short Course on Computer Hardware and Assembly May 1, 2015 If the system is unbootable, use a floppy to boot into the system and make changes. Do not reinstall as a first option. Have the data in a shared partition.