How Hardware and Software Work Together Chapter 2 How Hardware and Software Work Together

You Will Learn… About operating systems, what they are, and what they do How an OS interfaces with users, applications, and hardware How system resources help hardware and software communicate A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Introducing Operating Systems Software that controls a computer Acts as a middleman between applications and hardware Two main internal components Shell Kernel A+ Guide to Managing and Maintaining Your PC, Fifth Edition

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

The Shell and the Kernel A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Common Operating Systems DOS Windows 9x Windows NT, Windows 2000, and Windows XP Unix Linux OS/2 Mac OS A+ Guide to Managing and Maintaining Your PC, Fifth Edition

What an Operating System Does Provides user interface Stores, retrieves, and manipulates files and folders Manages applications Manages hardware A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Provides a User Interface Command-driven interfaces Menu-driven interfaces Icon-driven interfaces A+ Guide to Managing and Maintaining Your PC, Fifth Edition

A Menu-Driven Interface A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Manages Files and Folders Uses file system (FAT or NTFS) to track how clusters are used for each stored file Uses directories, subdirectories, and files Uses partitions and logical drives on hard drive A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Tracks, Sectors, and Clusters A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Files and Directories A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Partitions and Logical Drives A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Manages Applications Provides access to hardware resources Manages data in memory and in secondary storage Performs other background tasks A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Loading Application Software Using the Windows Desktop Shortcut icon Start menu Run command Windows Explorer or My Computer A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Using a Shortcut Icon to Load Software A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Real and Protected Operating Modes Real (16-bit) operating mode CPU processes 16 bits of data at one time Software has “real” access to hardware Protected (32-bit) operating mode CPU processes 32 bits of data at one time More than one program can be running, each one “protected” from others Uses preemptive multitasking A+ Guide to Managing and Maintaining Your PC, Fifth Edition

16-Bit and 32-Bit Software 16-bit software 32-bit software Written for Windows 3.x Accesses data 16 bits at a time Programs should not infringe on resources of other programs that are running 32-bit software Written for Windows 95 and later Windows OSs A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Manages Hardware Uses device drivers or the BIOS (system BIOS, startup BIOS, or CMOS setup) to interface with hardware Trend is to manage devices with device drivers rather than BIOS A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Manages Hardware (continued) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Uses Device Drivers to Manage Hardware Device drivers provide OS with software necessary to control devices 16-bit read-mode drivers Supported by Windows 95/98 32-bit protected-mode drivers Supported by Windows 95/98, Windows Me, and Windows NT/2000/XP A+ Guide to Managing and Maintaining Your PC, Fifth Edition

How an OS Uses System BIOS to Manage Devices To communicate with simple devices (eg, floppy drives or keyboards) To access the hard drive A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Using System BIOS A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Using System BIOS (continued) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

System Resources A+ Guide to Managing and Maintaining Your PC, Fifth Edition

System Resources (continued) Depend on certain lines on a bus on motherboard System bus components Data bus carries data Address bus communicates addresses (memory addresses and I/O addresses) Control bus controls communication (IRQs and DMA channels) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

System Bus Components A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Interrupt Request Number (IRQ) Line on a bus that device needing service uses to alert the CPU Managed by interrupt controller on motherboard Early motherboards: eight IRQs Second group of IRQs and second interrupt controller have been added to accommodate need for more devices A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Common Assignments for First Eight IRQs A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Second IRQ Controller A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Viewing IRQ Assignments Microsoft Diagnostic Utility (MSD) for DOS Device Manager for Windows 2000/XP and Windows 9x A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Viewing IRQ Assignments (continued) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Viewing IRQ Assignments (continued) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Memory Addresses Hexadecimal numbers assigned to RAM and ROM so the CPU can access both Used to access physical memory Often written in segment:offset form (eg, C800:5) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Memory Addresses (continued) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

I/O Addresses Numbers CPU can use to access hardware devices A+ Guide to Managing and Maintaining Your PC, Fifth Edition

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

Common Assignments for I/O Addresses A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Direct Memory Access (DMA) Channels Shortcut method that lets an I/O device send data directly to memory, bypassing the CPU A+ Guide to Managing and Maintaining Your PC, Fifth Edition

DMA Channels A+ Guide to Managing and Maintaining Your PC, Fifth Edition

OS Tools to Examine a System Device Manager System Information utility Microsoft Diagnostic Utility (MSD) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Device Manager Primary tool used to manage hardware devices under Windows 2000/XP and Windows 9x A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Device Manager ( continued) A+ Guide to Managing and Maintaining Your PC, Fifth Edition

System Information Utility Gives similar, but more, information than Device Manager BIOS version in use Directory where OS is installed How system resources are used Information about drivers and their status Additional information about software A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Using Windows System Information A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Microsoft Diagnostic Utility (MSD) Useful for viewing information about the system, including: Memory Video Ports Device drivers System resources A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Using MSD A+ Guide to Managing and Maintaining Your PC, Fifth Edition

Summary How hardware and software work together Different operating systems What they do How they work to control hardware devices How an OS provides the interface that users and applications need to command and use hardware devices A+ Guide to Managing and Maintaining Your PC, Fifth Edition