#### Asynchronous and Synchronous

Ricki Lambert Communications Technology Task 4 Bits and Bytes A bit is a singular digit represented by a binary number. A character is represented in computing terms but a code called ASCII There are 7 bits to an ASCII number With parity bit added there are 8 bits, parity is added to aid in error detection. 8 bits is equal to a byte. 1 1 0 This diagram represents an 8 bit binary number (1byte). The step represents a 1 and the flat part represents nothing. This number would then look like this, 100000001. In ASCII this represents the character A. Packet Structure Instead of sending singular characters it is possible to send many in one go, this is called a packet. For example we use the ASCII code to represent a sentence and this may take up to 50 characters. When sent in the form of a packet we must split the packet up, this is done by using control characters. The control characters are; SYN = Synchronise STX = Start of text ETX = End of text Above is an example of a packet structure used with Asynchronous sending. Bit and Baud Rate When the term bit rate is used, it means the amount of bits per second that are sent. A single character is to be sent for example, the character is ASCII code is made of 7

• Word count: 951
• Level: AS and A Level
• Subject: Computer Science

#### Computer Aided Design Package

Assignment P1/M1/D1 A company called Engineering ? Us have employed me to find out the cost, benefits and the drawbacks of upgrading from their current method of hand made technical drawing to using an up-to-date Computer Aided Design (CAD) package. This company designs and constructs office furniture to order; because of this work only begins on an item once the exact details of the item have been calculated and have the clients' approval. The current method which is used to gather the information that the designers need to make the drawings for the office is to send over a person to measure the location where the item or items of furniture will be located and how they will get the item into the building. After this has happened and the measurements have been given to the designers the designers will draw the blueprints by pen and paper. After they have drawn the design they will send the blueprint via one of the company's employee's to the client for him/her to look at and decide if it is what they wanted. If the client decided they liked the design the blueprint would be sent down to the workshop where they would start construction of the design. If the client didn't like the blueprint that the designers had made Engineering ? Us would find out from the client what was incorrect with the blueprints, then the designers would redesign the blueprints with the client's

• Word count: 7811
• Level: AS and A Level
• Subject: Computer Science

#### The main areas that will be focused upon in the interview are - Security and access to data - Manufacturers - The current process of how the returns are dealt with.

Pre-plan for the 1st Interview The main areas that will be focused upon in the interview are: * Security and access to data. * Manufacturers. * The current process of how the returns are dealt with. Security: * Has it been a problem in the past? * Any security measures that are in place now, for e.g. Is the user access restricted by password/ username login, etc? * A problem the user would like to see rectified in the new system? I need to know whether security is an issue worth tackling in the new system, and whether there are any particular sets of data are most importantly kept private. Manufacturers: * Any companies who have a noticeable trend in wrong deliveries; general mistakes. * What information regarding the manufacturers is stored, and where is it stored? I need to know of any problems caused by the manufacturers resulting in profit loss instead for the user, who has not been able to provide evidence due to the lack of organisation of the data. It is important to know how the amount of information that is stored on the manufacturers at this present time, so it would give a rough idea of the capacity required by the system. The user will be able to view outputs from selected time periods of a particular manufacturers performance. Current process of how the returns are dealt with: * Inquire the process as soon as the returns enter the shop to when the

• Word count: 4446
• Level: AS and A Level
• Subject: Computer Science

#### Storage devices in terms of computers.

There are two types of storage systems in terms of computers: > Primary storage: is the storage provided by memory in a computer > Secondary storage: storage provided by peripheral devices other than memory Primary storage: Memory - The amount of memory in a computer system determines the level of complexity of task that the system can handle. A single unit of memory is called a bit. A bit can store 0 or 1. Eight bits together are called a byte. Memory, and data storage capacity is usually measured in larger units. There are two classes of memory in a computer system: > Ram: (random access memory) > Rom: (read only memory) RAM is memory that can be both read and written to. It is used for storing data and programs while the computer is being used. Most RAM is volatile, i.e. it can only hold data while power is supplied to the computer. Once the power is turned off the contents of ram are lost. System settings such as date and time are stored in CMOS (complementary metal oxide semiconductor) RAM. CMOS RAM has a battery to keep the data. Therefore the data is not lost when the main power to the computer is closed. The main part of RAM may either be static or dynamic. > Static RAM is more expensive but allows for faster transfer of data > In dynamic Ram, the contents will "decay" even when the power is on, and so needs to be continually refreshed which slows down your

• Word count: 1252
• Level: AS and A Level
• Subject: Computer Science

#### System Analysis The aim of the Jewellery store system is to make the work easier to the jewellery store staff and to allow the customers and staff to explore the store quickly and easily. To manage the stock To figure out the total s

Contents AIMS AND OBJECTIVES OF THE JEWELLERY STORE SYSTEM 1 REQUIREMENT DESCRIPTION 1 SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC) 1 Systems Analyst 2 Phases of the SDLC 2 Phase 1: Problem Definition 2 Phase 2: Feasibility Study 2 Phase 3: System Analysis 3 Phase 4: System Design 3 Phase 5: Software Development 4 Phase 6: Testing 4 Phase 7: Implementation 4 . The user training 5 2. The conversion 5 Phase 8: Maintenance 5 THREE VIEW OF THE SYSTEM 6 Logical data models (LDM) 6 Data flow models (DFM) 6 Entity life histories (ELH) 6 The jewelry system in dataflow model 7 Task 1 AIMS AND OBJECTIVES OF THE JEWELLERY STORE SYSTEM There is much mass produced jewellery in the world. It is very difficult and impossible to keep the records of the vast amount of information about the jewellery using manual information system. The aim of the Jewellery store system is to make the work easier to the jewellery store staff and to allow the customers and staff to explore the store quickly and easily. * To manage the stock * To figure out the total sales of the month * To search for products which are on discount REQUIREMENT DESCRIPTION The system is to maintain order level for individual jewellery items as well as produce monthly total sales figures for the whole store. If a customer orders for an item the order should be sent to the store. If the item is not available

• Word count: 2300
• Level: AS and A Level
• Subject: Computer Science

#### The requirements of the user were to convert a paper based system of booking to an electronic booking system through my vast knowledge of ICT. This involved creating a logo, an invoice, the actual booking system and a set of two mail merge letters.

Evaluation of Unit 2 Introduction This document will outline all the major tasks and subtasks involved in the Unit 2 part of the three-unit course. Requirements The requirements of the user were to convert a paper based system of booking to an electronic booking system through my vast knowledge of ICT. This involved creating a logo, an invoice, the actual booking system and a set of two mail merge letters. The Logo The logo was one of the first assignments that we did and was one of the easiest for me. The main problem that I encountered was that it was hard for me to think of a design for my logo. It took me a while, but I eventually got my head around it. The strengths were that it was easy for me to replicate it but for some it was a lot harder because the designs were too intricate for them to replicate on the computer and had to use the electronic white board (Smart Board). If I did this again I would use Paint Shop Pro 7 for it would have looked a lot more professional. The Invoice The invoice was a lot harder for some and it would have been easier for me to use a less complex design. The invoice itself was easy to plan out but not to create. During the creation on the invoice, I actually forgot how to create a macro by using the control toolbox, so I spent some time scripting the macros. This was easy, for I do a lot of level, map and character scripts for a

• Word count: 598
• Level: AS and A Level
• Subject: Computer Science

#### The United Kingdom Awarding Body (UKAB) has asked me to design a system for the monitoring of its post-examinations re-marks.

Introduction The United Kingdom Awarding Body (UKAB) has asked me to design a system for the monitoring of its post-examinations re-marks. If a centre feels that the grade awarded to a candidate for an examination is lower than expected, the centre can ask for that script to be remarked. The UKAB expects all this to be completed within three weeks. All the details must be stored for the purpose of analysis and monitoring File Design External file name: Re-Mark.dat General name: Re-mark Description: Stores details of all current candidates Record structure Field name Field description Data type No. bytes CandName Candidate's Name String 6 CandNo Candidate's Number String 4 CenterNo Centre Number String 5 DateSub Date of the exam paper submitted Date 0 SubRef Subject Reference Code String 5 OrgMr Original Mark Integer 2 OrgGr Original Grade String 2 PaperRt Paper to be returned? String 3 RemarkedMr Remarked Mark Integer 2 RemarkedGr Remarked Grade String 2 DateRt Date of paper when returned Date 0 Record size 61 bytes Typical size of file 1 record per script. With 15 scripts= 990 bytes Data Flow Diagram Data Requirements Data to be input: The following details will be stored for the re-marks: * Candidate name * Candidate number * Centre number * Subject reference code * Original mark * Re-mark *

• Word count: 4329
• Level: AS and A Level
• Subject: Computer Science

#### Computers - History and Development

Computers: History and Development Nothing epitomizes modern life better than the computer. For better or worse, computers have infiltrated every aspect of our society. Today computers do much more than simply compute: supermarket scanners calculate our grocery bill while keeping store inventory; computerized telphone switching centers play traffic cop to millions of calls and keep lines of communication untangled; and automatic teller machines (ATM) let us conduct banking transactions from virtually anywhere in the world. But where did all this technology come from and where is it heading? To fully understand and appreciate the impact computers have on our lives and promises they hold for the future, it is important to understand their evolution. Early Computing Machines and Inventors The abacus, which emerged about 5,000 years ago in Asia Minor and is still in use today, may be considered the first computer. This device allows users to make computations using a system of sliding beads arranged on a rack. Early merchants used the abacus to keep trading transactions. But as the use of paper and pencil spread, particularly in Europe, the abacus lost its importance. It took nearly 12 centuries, however, for the next significant advance in computing devices to emerge. In 1642, Blaise pascal(1623-1662), the 18-year-old son of a French tax collector, invented what he called a

• Word count: 3423
• Level: AS and A Level
• Subject: Computer Science