Computer hardware1
- 1. Understanding Computer Hardware Continued… How fast is your computer? Depends on a lot of factors – Processor design – Clock Speed – Size of Cache memory – Bus Width – Math-Coprocessor Math- – Graphics processor, Video Processor, Audio Processor – RAM Size 1
- 2. How Fast is your Computer ? Also depends on performance of your hard drive Why? – The concept of Virtual RAM Average Access Time – Combination of how fast the drive is spinning and how fast the head head can move from track to track – HD: 6-12 ms 6- – CD: 80-800 ms 80- Data Transfer Rate (or Thoughput) Thoughput) – Max rate at which data can be transferred – Typically b/w 15/80 Mbps Performance improves with Defragmentation, scanning disk for Defragmentation, errors, and cleaning up unnecessary files Operating Systems CS101 – Autumn 2007 2
- 3. Operating Systems You have already had ample experience with at least one of them – IBM PCs commonly come with Windows XP Operating System… Some may have Windows 2000 System… on them – Macs have MAC OS operating system – Sun machines use UNIX or LINUX operating systems – Palm PDAs come with PalmOS Operating systems is how Bill Gates got so rich! 3
- 4. What is an Operating System? An operating system is a ‘program’, a piece of program’ software, rather than hardware It is the first program to be loaded in memory, after POST is completed It is a rather special program – it manages the computer and everything that runs on it Amongst other things, the operating system provides you with a User-Interface, so you User- Interface, can actually use the computer More on Operating Systems A microwave oven has a All desktop computers computer in it which have an operating system manages the keypad, the The operating system display, as well as does creates the ability to: computations about – Serve a variety of purposes cooking – Interact with the user in Microwave ovens do not more complicated ways need an operating At a simple level, OS does system, because they do two things the same simple task – Manages hardware and over and over again software resources An oven runs a single – Provides a way for the user program all the time to deal with hardware, hardware, without knowing all its details 4
- 5. Device Drivers Communication with all hardware not on the motherboard is done through device drivers Driver performs the role of a translator between hardware signals and programs E.g. Driver would translate a file sent to it by OS and convert it into series of laser pulses for a printer What does an Operating System do? User You can think of the operating Applications i.e. system as a factory manager, e.g. YOU who manages resources, MS Word, Calculator inventory, workers and jobs Operating System e.g. Windows 2000 Hardware CPU, Monitor, Keyboard 5
- 6. What does an Operating System do? The operating system manages a lot of things Including – Memory – Processor – Other hardware – Applications – File System Ref: http://computer.howstuffworks.com/operating-system.htm Types of Operating Systems Operating Systems for Desktops Single-User, Single-Task Single- Single- – At one time, only one task (application, program) can run on the computer – Eg. DOS, Palm OS Eg. Single-User, Multi-Task Single- Multi- – Most common type on desktops – E.g. Microsoft Windows, Apple’s MacOS Apple’ Multi-User Multi- – Allows several users to work simultaneously on a computer – Mainly run on servers – E.g. UNIX or LINUX 6
- 7. Types of Operating Systems Real-Time Operating Systems (RTOS) Real- – Normally used to control scientific machinery – Ensures that a given task occurs in precisely the time allocated for it – Typically not user friendly – Often is an embedded OS Embedded Operating Systems – Operating system built into the circuitry of a device, e.g. cell phones, medical equipment, bar-code scanners bar- – Eg Windows XP Embedded, Windows CE (also an RTOS), Symbian Network Operating Systems – Designed to work on network servers – Such machines often have multiple processors and fault-tolerance built fault- into them – High level of reliability is required – Eg. Windows NT Server, Windows Server 2003, Unix/Linux for servers, Eg. servers, Novell Netware Multi-tasking 7
- 8. PCB – Process Control Block Required Reading: Chapters 5b and 6 of text Useful link to understand more about operating systems… http://computer.howstuffworks.com/operating-system.htm Figure Acknowledgement: “How Computers Work” 6th Ed by Ron White Work” (Illustrated by Timothy Edward Downs) © Que Corp 2002 8