System Software

BIOS

Basic Input Output SystemA kind of ROM Execute routines Checking RAM, detecting hard disk, floppy disk, CDROM, …etc

Cold Boot

Restart the systemPress the reset button, power on the systemRun the routines in BIOSLoad the Operating System (OS) to RAMPass the control to OS if foundAn error message ‘Non-system disk’ will be displayed if OS cannot be found in hard disk, floppy or CDROM.

Warm Boot

Another way to restart the systemPress the Ctrl-Alt-Del keys, no need to power on or reset the systemDo not need to run the BIOS routinesSome start up processes have to be reloadedReset the system resources such as RAMUsually needed when running out of memory, system is unstable or after installation of new application software

Operating System

Act as the interface between Users(Application software) and hardwareProvide an environment for the user to develop and execute program without knowing the details of hardwareUser do not need to control the hardware directly, just call the routines in OSSuch as displaying text on screen, reading characters from keyboard, getting the position of mouse.

Functions of OS

Execution of program (Process management)Memory managementFile management (File read/write)Input and Output Devices ControlError handlingScheduling of jobsAllocate the system resources

Examples of OS

DOS – Disk Operating SystemWindows family such as XP, 2000, NT, CELinuxUnixMac OSIBM OS/2

DOS (1)

A command line interpreterAll the commands recognized are stored in the file COMMAND.COMCan execute files with file extension .com, .exe and .batCan access 1MB memory by default

DOS (2) – memory management

In order to run memory above 1MB, need extended memory or expanded memoryTo use extended memory (XMS), need to install HIMEM.SYS in the CONFIG.SYS fileTo use expanded memory (EMS), need to install EMM386.EXE in the CONFIG.SYS file

DOS (3) - Interrupt

Interrupt – a signal to tell the CPU to stop the current process, handle the outside request first, resume the process after fulfilling the request. E.g. saving a file to disk, printing a file, usually I/O requestInterrupt Vector Table – located in memory, use to store the addresses of the Interrupt Handlers.Interrupt Handler – programs to handle the interrupts.

DOS (4) – File Management

File Allocation Table (FAT)Similar to a content page of a bookStore the physical location(addresses) of files and directories in diskThe disk become useless if FAT is corrupted, files stored cannot be retrievedThe disk need to format again but all the files will be erased

DOS (4) - continue

DOS format disk to tracks and sectorsSectors are grouped to a logical unit, clustersThe size of cluster varies with the size of hard diskFile names are in 8.3 format. 8 for file name, 3 for file extension (see p.29).

e.g. abcdefgh.xyz

DOS (5) – adding new hardware

Device driver programs are needed whenever a new hardware is installed e.g. a printer driver, a scanner driver, a VGA driverThe OS does not support the installation of new driverThe new hardware have to configure manually

Windows (1)

Members include, windows 3.0, 3.1, 3.11, 95, 98, NT, Me, 2000, XPWindows 98, Me, XP home edition are for personal useWindows NT workstation, Windows 2000 professional, XP professional are for business purposeWindows NT server, 2000 server and XP server are for server purpose

Windows (2)

Graphical User Interface (GUI)Multitasking – can execute many programs at the same time. It divides the CPU time into small units called time-slices and allocates to different programs.Multi-user - server versions such as NT and 2000 can support multi-user processing. The time-slice technology is used to share the CPU time between different users. It is called Time-Sharing operating mode.

Windows (3) – memory management

It use virtual memory concept.Apart from the on-board memory RAM, it can use the free space on hard disk as the virtual memory, therefore applications that need a lot of system memory can be run at the same time.

Windows (4) – File system

It can use FAT32, FAT16 and NTFS filing systemFAT16 is used for backward compatibility with DOSFAT32 is used for windows 95 and 98NTFS is used for windows NT, 2000 and XP, which is more secure and efficient than FAT filing system.

Windows (5) – Adding new hardware

Support plug-n-play installationWhen adding new hardware, common devices can be detected, drivers are loaded automaticallyNo need to configure the hardware manually

Linux

Derived from UNIXCommand line interfaceCan install X-windows for GUI interface, two common shells are KDE and GnomeCommonly used in Servers, because of built-in network support, security, stability and minimal hardware requirement

Operation with file system-in windows

Using Window Explorer – a hierarchical file systemCreating and moving directories (folders)Copying, moving, renaming and deleting filesAllow long filenames up to 255 charactersSupport file extensions, which can associate the corresponding application

File Attributes

Read Only – file cannot be modifiedHidden – file name does not displayArchive – for backup purposeSystem – system file, vital for the system, usually hiddenTo change the file attributes – go to Options, View menu

Batch file

A text file with .bat extensionConsists of a sequence of commands or programs to be executed one by one when the batch file is executed.Usually run in DOS modeRefer to p.29 and p.58 for details

DOS commands (1)dir – listing files in current directorydir/w – listing files in wide formatdir/p – listing files by pagemd x – make directory xrd x – remove directory xcd x – change to the directory xcd .. – change to the parent directorycopy f1 f2 – copy f1 to f2del f1 – delete file f1cls – clear the screen

DOS Commands (2)

echo <text> – display the text on screenecho on – display the command it executes on screenecho off – do not display the commands it executes@echo off – suppress the display of first command ‘echo off’

DOS commands (3)

chkdsk C: - check error for drive C:format A: - format the disk in drive A:xcopy s d – copy all files in source directory to destination directorydeltree x – remove all contents under the directory x

System Utility Programs

Backup utility – for backup and restore filesNotepad – for editing textWordPad – for editing text with some formatting featuresCalculatorPaint – for drawing bitmap graphicsDisk defragmenter – to rearrange the files in hard disk, to reduce the access timeScanDisk – to scan the hard disk for errors, repair for bad sectors

Installation of System Software

Check the hardware requirementCreate a boot disk with CDROM driver if the system software is stored in CDPhases in installation Format the hard disk Copy files from CD-ROM, to speed up the process Decompress the files in correct folders Detection of hardware and installation of drivers Registration of software and connection to

Internet for more support (e.g. on-line user manual)