GCSE COMPUTER SCIENCE Computers 1.7 Control, Models and Virtual Machines

Examples of Control Systems include: - Air conditioning and central heating systems - Security systems and burglar alarms - Automatic doors - Manufacturing processes - Traffic lights and pedestrian crossings Microcontroller Sensors Output Devices ACTIVITY Draw this control system diagram in your book. This diagram show the different parts of a typical control system.

Write this definition of a microcontroller in your book. Microcontrollers Microcontrollers are small computers usually with a processor, memory and programmable input and output peripherals. ACTIVITY Write this definition of a microcontroller in your book. Arduino Microcontrollers are often embedded to provide automated control systems such as car engine control systems, robots and games consoles.

Write this definition of a sensor in your book. Sensors Sensors are input devices that are used to measure physical properties such as temperature, light, pressure, sound and humidity. They send signals to the microprocessor. ACTIVITY Write this definition of a sensor in your book. Data such as pressure, light and temperature is analogue. Computers can only work with digital data.

Write this definition of an actuator in your book. Actuators An actuator is a type of motor that is used as an output device for a control system. They allow the system to control movement or action. ACTIVITY Write this definition of an actuator in your book. An example is the Thames flood barrier, actuators are used to open and close the barrier gates.

Identify the control key terms from the descriptions: Activity 1 Identify the control key terms from the descriptions: Model Type Description Microcontroller Small computers usually with a processor, memory and programmable input and output peripherals. Sensor Input devices that are used to measure physical properties such as temperature, light, pressure, sound and humidity. They send signals to the microprocessor. Actuator Type of motor that is used as an output device for a control system. They allow the system to control movement or action.

Computational Models There are three different computational models used in computer science. You need to be able describe the characteristics of each of these models: Sequential Parallel Multi-Agent

Write the definition of a sequential model in your book. A sequential computational model is one in which instructions are executed one after another. There may be branches in the program, but the general principle is that each instruction follows on from the previous one. ACTIVITY Write the definition of a sequential model in your book.

Write the definition of a parallel model in your book. A parallel computational model is one in which each program instruction is executed simultaneously on multiple processors in order to get the results faster. Using multi-cores in processors is an example of parallel computing. It is by using parallel processing that super computers are getting faster and faster. ACTIVITY Write the definition of a parallel model in your book.

Multi-Agent A multi-agent computational model is one in which computer systems co-operate and co-ordinate with other agents to achieve their goals. ACTIVITY Write the definition of a multi-agent model in your book. Swarm robots are examples of multi-agents.

Activity 2 Identify the model type from the description: sequential, parallel, multi-agent. Model Type Description Sequential One in which instructions are executed one after another. There may be branches in the program, but the general principle is that each instruction follows on from the previous one. Multi-agent One in which computer systems co-operate and co-ordinate with other agents to achieve their goals. Swarm robots are examples of multi-agents. Parallel One in which each program instruction is executed simultaneously on multiple processors in order to get the results faster.

Virtual Machines A virtual machine is a layer of software that allows one computer to simulate another and to run more than one operating system.

Activity 3 Use the Internet to help you find the answer to the following question: Question Information Find out more information about Parallels. Find out more information about VM Ware. HINT Use their websites. Find out information such as cost, operating systems, features, uses etc.

Guest Operating System How Do They Work? The virtual machine acts as if it is a hardware machine, ‘deceiving’ the guest operating system into believing that it is installed on a computer when in fact it is not. With the continued increase in processor power, reduction in memory cost and increase in storage capacity, most desktop computers are capable of running many operating systems simultaneously. Guest Operating System Virtual Machine Host Operating System Hardware

Activity 4 Answer these questions in your own words: Question Answer What is a virtual machine? A virtual machine (VM) is an emulation of a computer system. Virtual machines provide functionality of a physical computer. Their implementations may involve specialised hardware, software, or a combination. Explain how a virtual machine works. A virtual machine is usually software that is installed on a computer. It allows a guest OS to be installed within this software. The guest OS then runs inside a window on the host OS, allowing you to use the guest OS at the same time as the host OS.

Activity 5 Use the Internet to help you find the answer to the following question: Question Answer What program is used to install Windows a on Mac computer? BootCamp What are the steps to installing Windows on a Mac computer using this program? Hint: Look on the Apple website! Check System Requirements Get a Windows disk image or CD/DVD Open Boot Camp Assistant Format your Windows partition Install Windows Restart your computer

Modelling Software is often used to model aspects of the real world. They can be used to make predictions about how real world systems will respond to different events. They allow us to try things out without putting people in danger or damaging equipment. An example is a flight simulator that allows trainee pilots to practice in a controlled environment safely.

Activity 6 Answer these questions in your own words: Question Answer Why is software used to simulate and model aspects of the real world? Computer models are cheaper to setup than alternative methods that could be used to predict what will happen in a system, eg building a prototype. Other benefits include being able to: make alterations and quickly see the outcomes, repeat tests several times over, learn from "what if?" scenarios and model dangerous situations safely. Give some examples of software models or simulations. Supermarket queues Stresses which will be borne by a new bridge Traffic flow in a new road system Grades for a GCSE class

Activity 7 Crossword Create a crossword based on this topic using the online crossword generator linked below. It should have a minimum of 10 questions. When you have finished, paste your crossword on to a Powerpoint slide and name it 1.7 Control Crossword. Print out one copy (include your name) and stick it in your book. http://puzzlemaker.discoveryeducation.com/CrissCrossSetupForm.asp puzzle maker criss-cross