1. Computer Software Operating Systems – Programs

2. Computer Language - Review We learnt that computers are made up of millions of tiny switches that can either be powered on or off. The only thing they can understand is on or off! (1 or 0) So how are we getting it to type, draw, play games, connect to other computers anywhere in the world, and so on?

3. Operating System Once the computer is powered up and turned on it needs to be able to recognize what devices are connected to it, how to respond to them and remember what the basic settings were. All of these are handled by groups of complex instructions and data collectively known as the Operating System (OS). Operating System is a software (as opposed to hardware, as you cannot see or touch it).

4. Remember BIOS? BIOS (Basic Input Output System) is a complex software component of the Operating System that is stored in the permanent unchangeable memory ROM. This is first and the most important software in the computer. Without this, the computer will just be a very primitive electrical device (like calculators), into which you have to type several 1s and 0s, every time you turn it on and use it. Even turning the computer on to get to the login screen is a complex task…

5. The DOS Disk-based Operating System or DOS stored in the hard drive and brought to the RAM by the BIOS. DOS contains all other important, but non essential parts of the Operating system. It is stored in the hard drive and loaded to the RAM by the BIOS. This process is called “Booting”, that is where the term “reboot” comes from.

6. Types of OS Two major commercial Operating Systems are Windows (Microsoft) and Macintosh (Apple). Researchers and Software Engineers are also fond of a more powerful, but less user friendly UNIX and LINUX. There are several versions of these - Windows (2000, XP, Vista) and Mac (System 8, Mac OS 9, Mac OS X Leopard)

7. Program A program is a set of instructions that tells the computer how to perform a specific task. For example, your favorite computer game is a program. In order for your computer to know how to play that game, you (or your parents) must first install the program from the game software - usually a CD. Installing the program means that you are copying the program or instructions that are stored on the CD on to your computer's hard drive. Programs can also be downloaded from the Internet directly to your hard drive. Many programs (especially games) are very large and would take up lots of memory space on your hard drive. To keep that from happening, these programs are designed to only copy part of the program onto your computer. The rest of the program stays on the software disk. The program cannot be run from your computer unless you have the disk in the disk drive so that RAM can read the rest of the program from it. Other programs install completely on your hard drive, so that they can be used without running the CD. This is very helpful with programs that are designed to help the user perform a specific task, such as typing a letter or creating a birthday card.

8. Types of Programs There are many different types of programs for the computer. They are grouped according to the tasks that they perform. Here are some very common types of programs and some examples of their uses: Word processing - letter writing, essays, writing stories Database - address books, mailing lists Spreadsheets - storing financial information Research - encyclopedias, informational programs Entertainment - games, music/video programs Education - skill practice games, tutorials, how-to programs Desktop Publishing - creating birthday cards, newsletters, etc.

9. Programming Language We learnt that Computers can only understand Binary Language (1s and 0s). Computer Programmers are people who write these codes to create programs and in order to make their jobs efficient, they invented something called a Programming Language and Interpreters which convert them to Binary Language. This way, the programmers do not need to remember all the bits and bytes combinations. Programming allows people and computers to communicate more easily.

10. Choose the right program… (Use Notepad to type your answers. Save as Lesson 5 under Lessons folder) What type of program would you use to do these tasks using a computer? Your choices are – Research Spreadsheet Education Database Entertainment Desktop Publishing Word Processing Note: Type the entire task and your program choice.

11. Want to know more? For more information, visit the following resources – –http://www.programmingbasics.org/en/gettingst arted.htmlhttp://www.programmingbasics.org/en/gettingst arted.html –http://www.linux.org/info/http://www.linux.org/info/ Also look up the keywords – Pseudocode, Algorithms, Debugging.