What four tasks are common to ALL computers? (Please select the correct order.)

Input information --> Process & Store information --> Output information

Output information --> Process & Store information --> Input information

Process and Store information --> Input information --> Output information

Input information --> Output information --> Process & Store information

Below are lists of different computer hardware devices. Which list ONLY shows INPUT devices?

mouse, keyboard, microphone, scanner, document camera

scanner, mouse, speaker, microphone, keyboard

keyboard, headphones, projector, microphone, mouse

printer, projector, speaker, headphones, monitor

Below are lists of different computer hardware devices. Which list ONLY shows OUTPUT devices?

printer, projector, speaker, headphones, monitor

monitor, mouse, speaker, microphone, headphones

3D printer, headphones, projector, microphone, mouse

mouse, keyboard, microphone, scanner, document camera

Which best describes the function of the motherboard?

It is the backbone that ties the computer's components together at one spot and allows them to talk to each other.

It controls the processing and storage of information.

How a Computer Works

How a Computer Works 4th & 5th

In this video we take a look at the 0:02 fetch to code 0:03 execute cycle including its effect on 0:06 the various registers we've previously 0:12 [Music] 0:14 discussed a computer is defined Definition 0:17 as an electronic device that takes an 0:20 input 0:22 processes data 0:25 and delivers output 0:29 in this simple example you can see we're 0:31 taking the input 5 0:35 we're multiplying it by 2 that's our 0:37 process 0:39 and we're outputting 10. 0:44 but this could be way more complex for 0:46 example of a game console 0:48 the input could be the buttons you press 0:50 on a controller 0:53 the processes would then be carried out 0:55 by the console itself 0:59 and the output would be some form of 1:01 update to a monitor 1:02 and sound out for a speaker possibly 1:04 vibration feedback through the 1:06 controller 1:10 to process data a computer follows a set 1:13 of instructions 1:14 known as a computer program 1:18 if we take the lid off a typical desktop 1:20 computer we can identify 1:22 two critical components the memory 1:26 that stores the program and the central 1:29 processing unit or processor 1:31 which is under this large fan and 1:33 carries out the instructions 1:37 a computer carries out its function by 1:40 fetching 1:41 instructions decoding them and then 1:43 executing them 1:44 in a continuous repetitive cycle 1:46 billions of times a second 1:48 let's look at each of these stages in a 1:50 little more detail Fetch 1:53 so let's start with the fetch stage the 1:55 very first thing that happens 1:57 is the program counter is checked as it 2:00 holds the address 2:01 of the next instruction to be executed 2:07 the address stored is then copied into 2:09 the memory address register 2:14 the address is then sent along the 2:16 address bus to main memory 2:18 where it waits to receive a signal from 2:21 the control 2:22 bus so it knows what to do 2:27 as we want to read the data that's 2:29 stored in memory address 2:30 0 0 0 0 the control unit sends 2:34 a read signal along the control bus to 2:36 main memory 2:41 now main memory knows the data needs to 2:44 be read 2:45 the content stored in memory address 000 2:49 can be sent along the data bus to the 2:51 memory data register 2:56 now as we're currently in the process of 2:58 fetching an instruction 3:00 the data received by the memory data 3:03 register gets copied 3:04 into the current instruction register 3:11 the instruction effectively has now been 3:14 fetched from memory 3:16 just before we proceed to the decode 3:18 phase we now 3:19 increment the program counter so that 3:22 the address it contains 3:24 points to the address of the next 3:26 instruction which will need to be 3:30 executed 3:32 the instruction now being held in the 3:33 current instruction register 3:35 is ready to be decoded 3:39 now as we mentioned in the previous 3:41 video the instruction is made up of two 3:43 parts 3:44 we have the op code that's what it is we 3:47 need to do 3:50 and we have the operand what are we 3:53 going to do it to 3:55 now the operand could contain the actual 3:57 data 3:58 or indeed it could contain an address of 4:01 where the data is to be found 4:06 by decoding this instruction we can see 4:08 the operation we need 4:10 is a load operation so we need to load 4:14 the contents of memory location0101 4:18 into the cpus accumulator 4:25 in the exam a simple model will be used 4:27 to describe the 4:29 structure of any given instruction 4:32 you're not going to be expected to 4:34 define how an opcode is made up 4:36 but simply to interpret opcodes in the 4:39 given context of an exam 4:40 question in the example here 4:44 you can see there's a total of 16 4:46 different opcodes available 4:48 and this is because we're using four 4:50 bits for our representation 4:56 so now we've fetched the instruction and 4:59 we've decoded it so we know what we need 5:00 to do 5:01 we're finally ready to execute it 5:05 so we now send address 0101 5:08 to the memory dress register 5:13 now we're in the memory address register 5:15 we can finally send the address 5:18 down the address bus to main memory 5:24 this time we want to read the data 5:26 that's stored in memory 5:28 and so the control unit again sends a 5:30 read signal along the control bus 5:36 so main memories now receive an address 5:38 and a read signal 5:40 so the content stored at memory location 5:43 0101 5:44 can now be sent along the data bus back 5:46 to the cpu 5:47 and into the memory data register 5:54 finally the contents of the memory data 5:56 register are copied to the accumulator 5:59 and this is one of a number of general 6:00 purpose registers found in the cpu 6:04 this first instruction is now complete Branching 6:11 so what does this program actually do 6:14 you should be able to work it through 6:16 carefully and figure it out 6:19 we're now pointing instructions zero 6:21 zero zero one in the program counter 6:23 and we're ready to fetch the second 6:25 instruction 6:27 at the end of this video we're gonna 6:29 provide you with the answer 6:34 so let's talk a second about programs 6:37 that branch 6:40 on the left here we have a very simple 6:42 piece of pseudo code 6:44 line zero says first execute this line 6:46 of code 6:47 line 1 now execute this line and then 6:50 line 2 says 6:52 if the age is greater than 18 then 6:56 we're going to execute lines 3 and 4 6:58 otherwise 6:59 we're going to execute lines six and 7:02 seven 7:03 so this program doesn't necessarily 7:05 follow strictly in sequence from line 7:07 zero through to seven there's a chance 7:10 here the program may branch and jump 7:14 around 7:16 so we're going to pretend that this 7:17 program has been loaded into memory 7:20 each line of code on the left here has 7:23 ended up 7:24 as a location in memory now this is not 7:27 strictly how this would happen in this 7:28 one-to-one way 7:29 but for the purpose of example it's 7:31 absolutely fine 7:35 so the program counter starts by 7:37 pointing to memory address zero 7:39 and we fetch the first instruction 7:41 decode it and execute it 7:44 it then updates and tells us the next 7:47 instruction 7:48 is zero zero zero one because remember 7:50 the program counter is being incremented 7:52 so we fetch it decode it and we execute 7:55 line one of our program 7:59 we then fetch line two which in binary 8:01 is one 8:02 zero 8:06 now at this point depending on what 8:10 happens during the execution 8:11 of line two the program may be required 8:15 to fetch line three from memory or 8:18 line five from memory 8:25 so let's look at how this actually works 8:27 because we've said the program counter 8:28 simply gets incremented 8:31 well in the current instruction register 8:33 we have an instruction with the op code 8:36 0 1 1 0. 8:41 now when we look this up in the decode 8:43 unit we discover that this 8:45 code means branch always 8:51 this replaces the value held in the 8:54 program counter 8:56 with the contents of the operand that's 8:58 the second part of the instruction 9:01 from the current instruction register so 9:03 this case 9:04 one zero zero one 9:09 now when the next fetch cycle begins the 9:12 program counter is obviously checked 9:14 and as its contents have been previously 9:16 updated to a new memory location 9:19 and not simply incremented the program 9:22 effectively is able to jump 9:24 around memory 9:28 so having watched this video you should 9:30 be able to answer the following key 9:32 question 9:33 how does a cpu work 9:39 okay so let's um answer the question we 9:41 posed 9:42 earlier what did that program actually 9:48 do 9:50 so this is the first fetch to code 9:53 execute cycle 9:55 and this is the one that we ran through 9:57 in detail earlier 9:58 it effectively loaded the contents of 10:01 the memory 10:02 stored at location location0101 10:05 into the accumulator in other words 10:08 the dna number 3 is moved 10:11 from memory into the cpu 10:18 we then proceed onto the second fetch 10:20 decode execute cycle 10:23 now this one adds the contents of memory 10:27 located at 0 1 1 0 10:30 to the current contents of the 10:32 accumulator 10:34 so in other words the dna number one 10:38 because that's what's stored at address 10:40 zero one one zero 10:43 is added to the number three that was in 10:45 the accumulator 10:46 the results are stored back over the 10:48 accumulator 10:49 so effectively we've done three plus one 10:53 equals four 10:58 the third fetch to code execute cycle 11:00 stores the contents which are in the 11:02 accumulator 11:03 into memory location zero one one one 11:07 and that's because the op code the first 11:09 part of this current instruction 11:10 zero zero one one is the command to 11:13 store when we look it up in the decoder 11:15 unit 11:16 so in other words the result of the 11:17 previous calculation three plus one 11:19 equals four 11:20 is now written back into main memory 11:28 the fourth fetch decode execute cycle 11:30 outputs the contents of the accumulator 11:33 remember they were copied into main 11:34 memory but they're still held in the 11:35 accumulator 11:37 so in this simple abstraction the number 11:40 four is now 11:41 output to the user so they can see the 11:43 result of the calculation 11:49 the fifth and final fetch code execute 11:51 cycle 11:52 brings a halt to the current program 11:58 so this very simple program which has 12:01 five 12:02 fetch decode execute cycles has 12:04 performed the calculation 12:06 three plus one is then stored the result 12:09 in main memory 12:10 and displayed the result four to the 12:12 user 12:13 and in a high-level language this may 12:15 look something very similar to the 12:17 following two lines of code 12:20 sum variable equals num1 plus num2 12:24 print sum to the user 12:27 so you can start to get an appreciation 12:29 here of how the high level code you 12:32 write actually ends up being fetched 12:34 decoded 12:35 and executed inside a processor 12:38 of course your processor is doing 12:40 billions and billions of these 12:42 operations a second 12:43 which when you think about it is really 12:45 very impressive 12:52 [Music] 13:03 you. make 10 questions for a standerd of a level

Learning is brain change (1) Everybody has a brain, but not many people know how the brain works. Some people believe that the brain is like the hard disk of a computer. We use it to store files-images, language (words, texts, sounds) and other data. Others compare the brain to a huge container or cupboard with lots of little drawers, shelves and boxes in it. We put information into these boxes and hope to find it again later. (2) The brain is not a computer disk, and it isn't a container. Look at the picture here. It looks a bit like weeds in a garden, doesn't it? The picture actually shows a child's neocortex - a part of the brain. You can guess what happens — more 'weeds" grow as the child gets older. Scientists call these neuronal networks. The networks grow around our neurons, or nerve cells. What makes them grow? Learning! Learning is brain change, says Professor James Zull from Case Western University in Cleveland, Ohio, USA. "Without learning, nothing changes in the brain. For every new word you learn in your English lesson, every puzzle you solve in maths, every new song you learn to sing, a neuronal network grows in your brain and the brain changes. (3) The more neuronal networks we grow, the better we can think and the better we remember. You may wonder if there is anything you can do to make the networks in your brain grow better. Professor Zull says yes, there is. He says that brain change is strongest when a) you are interested in and like what you are learning, b) you are in control of what you learn and c) you get challenging tasks that make you think hard and concentrate. Understanding a challenging task makes you feel good and develops your brain!

Soon computers and other machines will be able to remember you by looking at your eyes! The programme works because everyone’s eyes are different. So in the future you won’t have to remember a number when you want to use a machine or take money out of a bank. You’ll just have to look at the machine and it will be able to tell who you are. The eye-recognition（识别）programme is already being tested in shops and banks in the USA, Britain, Spain, Italy and Turkey. Soon, this technology will take the place of all other ways of finding out who people are. However, scientists are working on other systems. Machines will soon be able to know you from the shape of your face or hand or even your smell! We already have machines that can tell who you are from your voice or the mark made by your finger. Eye-recognition is better than other kinds because your eyes don’t change as you get older, or get dirty like hands or fingers. And even twins have different eyes, so the programme can be up to 94％ correct, depending on how good the technology is. Some programmes may only be right 51％ of the time. In Britain, it was found that 91％ of people who had tried it said that they liked the idea of eye-recognition. In the future your computer will be looking at you in the eye. So smile!

How Does a Computer Vires Work&

Gever Tulley is a computer scientist from California. In 2005, he started a summer programme for children called Tinkering School. The idea was that children can learn important skills for life by building things together. Gever Tulley and his team help the children to think big and create plans for innovative things they want to build. Children have made fantastic things since the school started. They have built a rollercoaster. They have made a rope bridge from plastic shopping bags. They have made tree houses, wooden motorbikes and boats. At Tinkering School, children get all kinds of materials like wood, metal, plastic, nails and ropes. They get lots of real tools too, such as knives, hammers, screwdrivers and power drills. Some children have cut themselves when using a knife, or hurt their fingers when using a hammer. Tinkering School has been around for many years now, but nobody has ever suffered a serious injury in all those years. This is because there are strict health and safety regulations they must follow. The children always learn how to use the tools safely and they must wear the right clothing and protection at all times. Gever Tulley's ideas have worked very well. A lot of children have gone to his summer schools over the years. In 2011, Gever Tulley and a colleague decided to create a 'real' ! school, called Brightworks, in San Francisco. The school is very small-it only has 20 students aged 6 to 13. Brightworks is based on the same principles as Tinkering School. Since it started, Brightworks has been written about a lot. Most of those articles have been very positive. They have praised the quality of the school. They have found the children are more motivated than at many other schools. But since the beginning of the school there have also been critical voices. Some people have said that children are not learning enough at Brightworks. They feel that students and teachers are just 'playing around' all the time. The students at Brightworks seem to love their school. We spoke to 12-year-old Tina Cooper. She has been a student at the school since last October. 'Since I started here, I've never sat in a 'normal' class with a teacher,' she told us. 'But it's been a very exciting experience. I've worked hard at my new school for eight months now, and there hasn't been one single moment when I found it boring. Before, I was bored quite often.'

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