A+ Guide to Managing and Maintaining Your PC Fifth Edition Chapter 2 How Hardware and Software Work Together

2 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Software A set of instructions that controls hardware to work The “intelligence” of a computer

3 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Operating Systems Software that controls the fundamental functions of a computer  Memory management  Data input/out  Applications execution  User interfaces  Networking  Data searching

4 A+ Guide to Managing and Maintaining Your PC, Fifth Edition OS as a Middleman

5 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Popular Operating Systems Windows 9x (95, 98, and me) Windows NT, Windows 2000, and Windows XP Linux DOS Unix Mac OS

6 A+ Guide to Managing and Maintaining Your PC, Fifth Edition File Systems A crucial part of an operating system Manage files on permanent storage devices (e.g., hard disks)  Organize files hierarchically into directories  Access files through path  Operate files/directories: create, open, rename, move, delete……  Read/write data from/to files

7 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Windows File Systems FAT (File Allocation Table)  Windows 95/98 NTFS  Windows NT/2000/XP

8 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Experience the File System

9 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Device Drivers Software that controls devices Obtain device drivers  Included in the operating system  Bundled with the device  Available on manufacturer’s web site Device drivers vs. system BIOS

10 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Practice: Device Drivers

11 A+ Guide to Managing and Maintaining Your PC, Fifth Edition System Resource A tool used by hardware or software to communication with each other  IRQ  Memory addresses  I/O addresses  DMA channel

12 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Interrupt Request (IRQ) A bus line that a hardware device uses to signal the CPU that the device needs attention Some lines have a higher priority than others Each IRQ line is assigned a number (0 to 15 except 2) to identify it IRQ 0 has the highest priority IRQ0 – system clock IRQ1 - keyboard

13 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Practice: Viewing IRQ Assignments

14 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Memory Addresses Numbers assigned to physical memory (RAM memory and ROM) Software can use these addresses to access memory Memory addresses are communicated on the address bus

15 A+ Guide to Managing and Maintaining Your PC, Fifth Edition I/O Addresses Numbers assigned to hardware devices that CPU can access a device Each device “listens” for these numbers and responds to the ones assigned to it I/O addresses are communicated on the address bus

16 A+ Guide to Managing and Maintaining Your PC, Fifth Edition I/O Addresses ( continued )

17 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Practice: Viewing I/O Addresses

18 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Direct Memory Access (DMA) Channels A faster communication method than IRQ Is used by hardware to transfer data directly from/to memory, bypassing the CPU Each DMA channel is assigned a number (0 to 7 except 4)

19 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Practice: Examining DMA Channels

20 A+ Guide to Managing and Maintaining Your PC, Fifth Edition OS Tools to Examine a System  Device Manager  Windows 2000/XP and Windows 9x  Primary tool used to manage hardware devices Third-party software

21 A+ Guide to Managing and Maintaining Your PC, Fifth Edition Summary What’s operating system? What are the commonly used operating systems? What’s file system? What are the file systems used in Windows? What’s device driver, and how a hardware device is managed by a device driver or system BIOS? What are system resources, and how do you examine system resources?