Hardware vs. Software
Computer systems consist of both hardware and software.
Hardware refers to anything you can physically touch.
o Keyboards, mice, monitors, and motherboards are all hardware.
Software consists of the instructions issued to the computer to perform specific tasks.
o The software on a computer system refers to the programs that make the computer run.
Types of Software
Two types of software are applications software and systems software.
o Applications software consists of programs to perform a specific task.
o Systems software consists of the operating system and all utility programs that are used to manage computer system resources.
Applications Software
Applications software is also called productivity software.
It allows an end user to perform some task.
The most commonly used categories of applications software are
o Word-processing programs
o Spreadsheet software
o Database software
o Presentation software
o Desktop publishing programs
o Games
Systems Software
Systems software consists of programs that coordinate and control the resources and operations of the computer itself.
The three categories of systems software are
Operating systems
Utility programs
Language translators
Systems Software—Operating Systems
Operating systems provide an interface between the user and the computer.
Many brands and versions of operating systems exist.
Operating systems are designed to work with a specific processor chip.
For example, Windows operating systems are designed to work with an Intel processor (or clone) and usually will not work on a Macintosh computer.
Systems Software—Utilities
Utility programs are designed to help perform housekeeping chores for the computer.
They can be designed to
o Manage the computer’s resources
o Do file management
o Format disks
o Copy files from one disk to another
o Back up data to disk or tape
Common Utility Programs
Systems Software—Language Translators
Computers cannot read program statements in programming language format, such as Visual Basic or Java program statements.
Language translator programs convert English-like software programs into machine code that can be understood by the computer.
Each converted English-like instruction may be translated into many machine code instructions.
Once converted to machine code, the program can be run and executed by the computer.
Microcomputer Operating System Interfaces
The operating system user interface
o It is the part of the operating system with which you interact when using your computer.
The two most commonly used types of operating system interfaces are:
Command-line interface: With this interface, you must type exact commands into the computer from a command prompt.
o This is not a user-friendly interface, and you must memorize commands and keywords.
Graphical user interface: Users manipulate on-screen icons to perform functions, usually with a mouse or other pointing device.
User Interface Comparison
The figure on the left shows a command-line interface, where commands are typed at the prompt.
The figure on the right is a graphical user interface (GUI), where users perform actions by clicking and manipulating icons.
Microcomputer Operating Systems
If your computer is a Macintosh, you most likely are using a Mac OS.
o Macintosh computers used one of the first GUI operating systems ever developed.
If your computer is a PC or is PC-compatible, you most likely are using one of these operating systems:
o DOS
o A combination of DOS and Windows
o A stand-alone version of Windows
The Mac OS
Macintosh computers were developed by Apple Computer.
Macintosh had one of the first GUI operating systems in which icons were used to represent programs and files.
To activate an icon, the user clicked it with the mouse.
This was also the first operating system to provide an on-screen help system.
The DOS Operating System
IBM introduced its first PC in 1981. Its operating system was called DOS, which stands for Disk Operating System.
IBM called it PC-DOS.
The operating system was licensed from its creator, Microsoft, who sold it under the name MS-DOS.
DOS was a command-line interface operating system in which the user had to enter commands at a screen prompt.
It was a single-tasking operating system, which meant that only one program at a time could be executed.
The Windows Operating System
Windows was Microsoft’s first GUI operating system, released in 1987.
The first versions were called operating environments because they acted as a shell around the DOS operating system and worked in combination with DOS.
Applications installed on a Windows system appeared as icons.
As with the Mac OS, the user activated a Windows program by clicking the icon.
Windows Versions
The earliest versions of Windows were labeled Windows 3.0, 3.1, and so forth.
The first true multitasking version of Windows was Windows 95.
This version also included support for networking computers.
Windows 98 improved on Windows 95 and offered Internet integration and support for the USB bus.
Windows 2000 was an update to Windows 98 and Windows NT. It included tools for Web site creation.
The latest version is Windows XP, which provides increased stability and device recognition.
Macintosh vs. Windows User Interface
The image on the left is an example of a Macintosh interface.
The image on the right is the Windows XP interface.
Embedded Operating Systems
Used on handheld and wireless devices
Three most popular systems are
Windows CE
Windows Mobile
Palm OS
The UNIX Operating System
UNIX is another early operating system that is still widely used today.
o It was developed by AT&T as part of their phone-switching system.
o It was developed to be a portable operating system.
That means it was meant to run on any hardware platform.
o It is a command-line interface system, although there are now several GUI interface products available for UNIX and Linux.
A UNIX System
Linux offers a graphical user interface shell for a UNIX operating system, as shown here. This provides greater ease of use while taking full advantage of UNIX’s speed and reliability.
Loading the Operating System
Booting is the process of starting your computer.
o The BIOS is activated.
o BIOS searches for the boot record.
o The boot record is loaded into RAM.
o The software drivers are loaded.
o The operating system (GUI) is loaded.
