1. OCR Computing AS @ OGAT 1.2.2 Applications Generation

2. What OCR need you to know 1.2.2 Applications Generation a) The nature of applications, justifying suitable applications for a specific purpose P97-98 b) Utilities P98-99 c) Open Source vs Closed Source P107-108 d) Translators: interpreters, compilers and assemblers P109-112

3. Different Types of Softwar e There are three types of software, these are: Systems Software / Operating Systems – you have recently cove red this. Utilities Software Applications Software TASKS 1.Give a definition of “Utilities Software” 2.Give a definition of “Applications Software”

4. Applications Software TASKS 1.Investigate each of the types of applications software listed, for each explain t he key features and give examples. 2. Discuss using word processing as an example how new technology e.g. smart phones/tablets has changed the way in which applications software is used. Browsers Audio & Video Editing Graphic Design Developer Communications Word Processing Spreadsheet Presentation Desktop Publishing Web Design

5. Utilities Software TASKS 1.Investigate each of the utility programs listed above, explain what they do, ho w they work and give an example of each. 2.Explain why you should not use defragmentation utilities on a solid state drive. Anti-Virus Disk Defragmentation Compression File Managers Backup Utilities

6. Open & Closed Source Sof tware TASKS 1.Describe the key features of closed source software. 2.Describe the key features of open source software. 3.Identify the advantages and disadvantages of each approach to distribution. 4.Discuss whether a school should move to using open source software where t hey can. There are two approaches to the distribution of software once it has been created, these are open or closed. Closed Source software – the source code is not released to t he public. This prevents amendments to the software being mad e to anyone other than those authorised. Open Source software – this is where the source code is made publicly available. This allows users to modify the program to sui t their needs.

7. Translators Programming languages are used to write programs and create the different s oftware types previously considered. However for it to be readable by the CP U, the source code of the program must be converted into binary (machine code). To do this translators are used. There are three types of translator which are used for different reasons, these are: Assemblers Compilers Interpreters TASKS 1.Explain the role of a translator. 2.Define the term “object code” 3.Define the term “machine code” 4.Define the term “source code”

8. Assembler An assembler converts assembly code into machine code. An example of assembly co de is shown the to the right: Assessbly Code section.data msgdb‘Hello, World!’ 0AH lenequ$-msg section.text global _start _start: mov edx, len movecx, msg mov ebx, 1 int80h movebx, 0 mov,eax, 1 int80h TASKS 1.Explain how assembly language is constructed. 2.What are the two parts of each instruction in ass embly language called? What do they do? 3.How many processes can be carried out in one li ne of assembly language? 4.Why is assembly language unlikely to work on an other processor? 5.What does an assembler do? High Level Code Print(“Hello World”)

9. Compilers & Interpreters Compilers and interpreters both translate high lev el programming languages into machine code so th at they can be read by the CPU. TASKS 1.Describe the key features of a high-level programmin g language. 2.Explain how an interpreter works. 3.Explain how a compiler works. 4.Describe a similarity and a difference between a com piler and an assembler. 5.Explain why an interpreter is useful for debugging a program? 6.Why is most commercial software provided as compi led code?