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SECTION 1: COMPUTER PROGRAMMING
There are many programming languages. To execute, they have to be compiled or interpreted. An IDE (integrated development environment) is used to write code, test for errors and translate a program.
Below shows the different types of High Level and Low Level Computer Programming Languages, the most most types of programming languages used are C#, JAVA, COBOL, Python, Scratch, etc.
Computer Programming Languages require specific wording, symbols and numbers to create a working script. Complex languages are programs such as JavaScript and C#. The easiest form of coding is block coding such as Scratch, which can help develop knowledge and understanding for COBOL and Python.
COBOL Programming Language
JavaScript programming Language
Scratch programming Language
Python programming Language
Translators - usually included within programming software - convert high-level code into machine code. Translators are assemblers, interpreters or compilers.
Assembler
'An assembler translates assembly language into machine code. Assembly language is a low-level language written in mnemonics that closely reflects the operations of the CPU.
Interpreter
An interpreter translates code into machine code, instruction by instruction - the CPU executes each instruction before the interpreter moves on to translate the next instruction. Interpreted code will show an error as soon as it hits a problem, so it is easier to debug than compiled code.
An interpreter does not create an independent final set of source code - source code is created each time it runs. Interpreted code is slower to execute than compiled code.
Interpreted languages include JavaScript, PHP, Python and Ruby. Interpreted languages are also called scripting languages. These are ideal for using within dynamic web applications. They are used for client-side and server-side coding, as they are small programs that are executed within the browser.
Compiler
A compiler translates the whole program into machine code before the program is run. It can be difficult to test individual lines of compiled code compared to interpreted languages as all bugs are reported after the program has been compiled.
The machine code is saved and stored separately to the high-level code. Compilation is slow but machine code can be executed quickly.
Java and C++ are compiled programming languages. Java is a high-level programming language which is compiled to produce bytecode which is then interpreted by a virtual machine (VM). Bytecode is code which is compiled and can then be interpreted.
James A. Rowling, the inventor of Java computer programming script.
KEY TERMINOLOGY:
- Interpreter - Converts the HLL program line by line into machine code.
- Assembler - Converts assembly language into machine language.
- DBMS - Collection of Data and other related information.
- COBOL - Used for business data processing.
- JAVA - Used to create web pages.
- Compiler - Converts the HLL program into machine code in one go.
SECTION 2: EXCEL (DESKTOP BOOK - pgs 86 - 124)
MS Excel features calculation, graphing tools, pivot tables, and a macro programming language called Visual Basic for Applications. It has been a very widely applied spreadsheet for these platforms, especially since version 5 in 1993, and it replaced Lotus 1-2-3 as the industry standard for spreadsheets. Excel forms part of the Microsoft Office suite of software.
A MS Excel spreadsheet is comprised of cells, which has a specific co-ordination made up from the Column (letter) and Row (number). Each cell is rectangular, however can be changed in size and length by adjusting the width of the columns or height of the rows.
An example of a MS Excel spreadsheet with a highlighted 'cell'.
Excel uses formulas (coding) to perform mathematical calculations. '=SUM' is the most common formula to create an addition, subtraction, multiplication or division calculation.
This Excel spreadsheet demonstrates a percentage total (%) has been calculated for cell 'E3' using a formula '=SUM(D3/C3)' and 'E4' using '=SUM(D4/C4)'.
Excel is also advantagous for creatin graphical representations of data, such as bar charts and pie charts.
Line Graph
Pie Chart
Section 3: MS WORD (DESKTOP BOOK - pgs 13 - 47)
The bar across the top of the Word application is known as the 'Ribbon'. This includes all the features used for creating a Word document.
'File', 'Home', 'Insert', etc. across the top of the Ribbon are called 'Tabs'.
'Clipboard', 'Font', 'Paragraph', etc. underneath the Ribbon are called 'Groups'.
The bar across the bottom of the Word application is called the 'Status Bar'. This is used for zooming in and out, indicating the page number and word count; and page viewing modes.
The large blank area of the Word document is called the 'Main Body of Text'.
The feature used for inputting the same text at the top of all document pages is called the 'Header'.
The feature used for inputting the same text at the bottom of all document pages is called the 'Footer'.
SECTION 4: MS POWERPOINT (DESKTOP BOOK - pgs 57 - 99)
MS Paint also has a 'Ribbon' bar at the top of the Paint application, which uses various 'Tabs' and 'Groups' of features.
The 'Status Bar' at the bottom of the application indicates the slide number, various slide view modes and also the zoom feature. Furthermore, as an additional feature, 'Notes' can be included for each slide as a reference during PowerPoint Presentations.
To format an image, select it within the slide page and use the various 'Picture Format' tools on the 'Tab' to change the image features.
To make your image(s) and text move/appear during a slide show presentation, select each one and use the features on the 'Animation' tab to make it move.
To make each slide appear in a unique way, use the 'Transitions' tab to select the type of change you would like your slideshow presentation to produce.
SECTION 5: COMPUTER VIRUSES AND THEIR EFFECTS
A computer virus is a program that is secretly introduced into a system in order to corrupt or destroy data. It infects the computer negatively by altering the way the computer works, without the user's knowledge or permission. It spreads from one computer to another computer. A virus destroys or corrupts the data files on the computer system.
Virus is a Latin word which means 'poison'. Virus stands for 'Vital Information Resource Under Seige'. It does stand alone but needs a host file or program to replicate itself.
You may also define it as an undesirable and unwanted program file or routine that corrupts files, replicates itself, replicate other files or in some other way degrade or even shutdown a computer system.
This diagram demonstrates the different types of Viruses in existence that can affect a Computer.
The first computer virus that was known publicly is 'Elk Cloner'. It was created by Rich Skrenta (a middle school student) in 1982. This virus attached itself to the Apple DOS 3.3 operating system and spread through a floppy disk.
The first PC virus was a 'boot sector' virus called 'Brain'. It was created in 1986 by two brothers to prevent pirated copies of software they had written.
Since the mid-1990's, 'Macro Viruses' have become common. These viruses spread through Excel spreadsheets and other Microsoft Office documents.
Today, one of the most common means of a virus infection is through the Internet. E-mails are also one of the most prominent means to spread a virus.
Elk Cloner, the first publicly known virus in 1982.
Boot Sector viruses reside in the boot sector of hard disk or floppy disk. The boot sector is the area of a hard disk or floppy disk that stores valuable information. They cause damages to the stored information. Some of the boot sector viruses are Polyboot B and AntiExE.
'Brain', the 'Boot Sector Virus created in 1986.
A 'Trojan Horse' is a program that appears to be beneficial at first glance but actually damages the computer once it is run. They can steal the information from the computer. 'Beast' and 'Zeus' are examples of a Trojan Horse. Some examples of damage by Trojans are:
- Corrupting and encrypting files.
- Copying fake links which lead to false websites.
- Opening and closing CD-ROM tray.
- Restarting the computer.
- Randomly shutting down the computer.
- Slowing down your computer.
- Taking screenshots.
- Logging keystrokes to steal information such as passwords and credit card numbers.
An example of a Trojan Horse virus on a monitor.
E-mail Viruses spread through e-mails and the attached files. Once an infected attachments is opened, the virus infects the computer system. Some of these viruses replicate themselves by automatically e-mailing everyone in your e-mail address book.
Example of an E-mail virus.
Other types of viruses are:
- 'File Viruses' which infect programs or executable files (files with .EXE or .COM extension). When an infected program is run, the virus becomes active and infects the executable files on the computer. For example, Cascade and Sunday are file viruses.
- 'Worms' which is a malware program that duplicates itself. This virus does not need any host file to attach. Worms can spread very fast and in great numbers. For example, Sasser and Blaster.
Example of a worm virus.
The various ways a virus can enter the computer system:
- Portable Devices - Floppy Disk / CD / USB Memory Stick, etc. that is already carrying the virus on it.
- E-mail - Virus may enter into your computer system through e-mail attachments.
- Internet - Virus may enter through various malicious websites. This can be through downloading infected files which put your computer at risk.
- Computer Network (Server) - A computer system connected by a large/main computer called a 'server' and constantly share information. Any infected file may spread the virus.
Symptoms of a computer virus:
- The computer might run slower.
- It might corrupt your system files.
- It might might make some programs faulty or corrupt.
- It might steal important information from your computer and send them to other people through the internet.
- Application programs on the computer do not work correctly or smoothly.
- The computer locks up by itself frequently which means that it stops responding to your command.
- It makes endless copies of infected files on the system.
- Strange sounds or beeping noises come from the computer monitor.
- The hard drive often runs out of free space.
SECTION 6: PRINTABLE REVISION WORKSHEETS
To compliment the learning in your child/ren's Computing lessons, why not download these printable worksheets relating to the Topics taught in class and the Desktop: Computer Science Books.
Computing Grade 7.pdfPage updated
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