COMPUTER Chapter 1 ( 25-28),

Chapter 4 - Discovering Computers & 2013

I. Software or Computer Program - The step by step electronic instructions that tell the computer what to do or how to perform some given task. Software is what determines the versatility and environment of your computer. Most if not all software resides on some form of secondary storage media. Software is written or created by a computer programmer. Every computer requires both “system” and “application” software. The communicates with the hardware, the determines what tasks a user can perform.

II. Software categories

A. System software - Instructions that directly control hardware.

1. System software is comprised of the following:

a. Operating system (O.S.) - the fundamental instructions that control your computer’s basic hardware functions. Loaded automatically during the boot process (when you turn your computer on). An O.S. can be loaded via either a "cold" or "warm" boot. Can you have more than one operating system? Yes

Fall 2014 1 (dual-boot system) but they can’t run at the same . O.S. examples include:

1.) DOS - disk operating system, product of Microsoft. Prior to Windows was the most popular operating system in the PC world. Seven versions were developed. (1981-1994)

2.) OS/2 - joint venture between IBM and Microsoft, introduced with the IBM PS/2 in the early 1980’s. Because of proprietary nature met with limited success. In other words if you didn't own a PS/2 you didn't have access to OS/2, OS/2 only ran on the PS/2

3.) MAC OS – proprietary O.S. used in Apple/Macintosh PCs, pioneers in the “GUI”. The GUI was derived by Xerox laboratories. OS X Tiger is the current version. The current MAC OS has more Windows compatibility (or vice versa)

4.) UNIX – gained popularity in early networking environments, first to support multi-tasking.

a.)) is a variation of UNIX tailored for PCs. Some versions of LINUX are free. LINUX is open-source which means if you know how you can change or customize it. Different variations of LINUX – Red Hat, Mandriva, Suse. Little or no technical support, not compatible with all application software.

5.) WINDOWS - Microsoft’s successor to DOS. Gained instant popularity because of the GUI environment. Several versions of Windows operating systems exist and Windows is by far the most dominant operating system for desktops, PCs primarily. Windows 95 was the first true Windows operating system. There were other Windows versions before 1995, if they were not operating systems what were they?

6.) Network operating systems (NOS) run on servers and are used to manage LANs, not typically used on a standard PC. These O.S.'s are far more robust and expensive - we'll discuss these later during our communications lectures

8.) Non-PC systems (Super, Mainframe, Mini, etc.) use proprietary operating systems. Systems such as palm pilots, mainframes, would use a non-Windows O.S.

b. Device Drivers – Programs initially stored on a floppy, CD ROM, USB, or the web, that accompany all hardware devices. These programs contain instructions provided by the manufacturer of that device that tell your operating system how to recognize and operate their associated . These programs are initially installed when the new hardware is installed and

Fall 2014 2 thereafter loaded into memory when booting occurs. Every hardware device requires a driver. How many drivers would an average system require?

c. Utilities - Special programs designed to perform non-routine functions not associated with the operating system. Tasks associated with system maintenance such as disk repair, formatting, compression, data recovery, and virus detection, are examples of operations involving these types of programs. These programs are typically included in your operating system package or can be purchased from a third party vendor. Some utilities are packaged as suites.

d. Programming languages – All software is written or expressed in a programming language. Programming languages are special programs that provide the code for software instructions, software instructions have to be expressed in a code or language. COBOL, BASIC, C++, & are examples of common programming languages.

1) Software code written in a programming language is said to be in a “high level language” or “”. Source code cannot be used by a computer until it becomes "object" code.

2) A or interpreter translates the source code into “machine language” (binary numbers, 1, 0) or “object code”. If a program is not in “object code” it can’t be understood by the computer. A computer only understands instructions expressed in "1's" and "0's". NOTE: This section on programming languages is not in your textbook although it is mentioned briefly on page 28

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Figure 1Source code sample - not binary

3) If you are not developing software you have no need for a programming language

B. Application software - Application software interacts with system software to enable your computer to perform a specific task. Tasks such as word-processing, accounting, or playing computer games would fall into the category of application software. Unlike system software which is loaded automatically when you turn the computer on, application software is loaded by the user from a menu or desktop icon.

1. Types:

a. Productivity software - helps you work more efficiently

Fall 2014 4 1.) Word-processing - to produce documents (WORD)

2.) Spreadsheets - use numbers and formulas to create worksheets and graphs (EXCEL)

3.) Database - used to create large databases from which specific, special reports can be extracted (ACCESS)

b. Business software

1.) Accounting

2.) Payroll

3.) Accounts Receivable

c. Entertainment - games, drawing, graphics

d. Education - online tutorials, encyclopedias

e. Multimedia – image, audio, & video editing

f. Others mentioned in your text book (Home, Communications, etc.)

g. Document management software allows file formats to be converted into a universal format not dependent on the source application. An example would be PDF (Portable Document Format) files. The reader allows you to view .PDF files. Most OFFICE software allows you to change the format of the native data to .PDF

h. Web Applications - allow users to interact with software at a web site

2. Software suites or packages – Compatible application programs belonging to a specific group, sold as a single package. Programs within the suite generally allow for data integration between the differing applications. For instance you can take a data object created in WORD and use it in EXCEL although they are entirely different applications. The file extension identifies the format of the data. Characters appear differently in each program because the format is different. Example of a suite is what we're going to be using in our course, Microsoft OFFICE.

3. Patches, Updates – Supplemental code or instructions added to a program to correct a program defect or to add new features. It is virtually impossible for a programmer to identify every flaw, defect, or omission in a program until the program is in operation. Once those flaws are detected they become available over the Internet as a "patch" or "update", usually supplied by the software vendor. The patch or update is the code or instructions to be used to provide a remedy to the identified flaw or omission. Most updates are available on the Internet to legal owners of the purchased software. Update alerts usually appear in the Windows desktop notification area.

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