2 RAM – Random Access Memory Computers use two types of storage: Temporary and PermanentLong-term storage is for information computers use again and again, such as the instructions the computer prepares itself with every time you turn it on. These instructions are stored in read only memory (ROM), a type of memory that does not accept new information.RAM is a volatile storage device meaning that when the computer is switched off everything stored on this temporary storage device will be lost.The more computer memory, the better the computer will run and the better it will handle programs and software.RAM is generally measured in Mhz, and most commonly seen in the types of SDRAM, DDRRAM, DDR2RAM and now DDR3 SDRAM.
3 The words 'random access memory' refers to the fact that any byte of data can be accessed directly by the computer instead of it searching in order till it finds it.RAM operates at very fast speeds and is crucial to the health of a computer. RAM was measured in ns (nanoseconds) which equals one billionth of a second but with the introduction of SDRAM is now measured in MHz (megahertz).Like many components RAM is placed into slots in the motherboard where it can be upgraded.Memory is needed for all computer operations and it is important to have enough.So what is Computer RAM?
4 Types of RAMThere are two basic types of RAM: Dynamic RAM (DRAM) and Static RAM (SRAM).Dynamic RAM is the more common and needs to be refreshed thousands of times per second.Static RAM does not need to be refreshed making it a lot faster but also much more expensive.
5 DDR RAMDDR RAM or DDR SDRAM. It stands for: Double Data Rate Synchronous Dynamic Random Access MemoryDDR SpecificationsDDR RAM (Double Data Rate) which means it can transfer double the data without increasing the clock speed.Typical clock speeds were 100Mhz, 133Mhz, 166Mhz and 200MHz.Megabyte(MB) and Gigabytes (GB) measure the size of DDR SD-RAM. They vary in size from 128mb-1Gb. The common sizes are 256mb, 512mb and 1Gb. DDR2 RAM and DDR3 RAM have both increased the speed and size even further and they are similar prices so if possible go for DDR2 or DDR3.
6 DDR2 RAMDDR2 RAM or DDR2 SDRAM is a type of computer memory. It stands for: Double Data Rate 2 Synchronous Dynamic Random Access Memory.DDR2 SpecificationsDDR2 RAM (Double Data Rate) which means it can transfer double the data without increasing the clock speed. Typical clock speeds were 100Mhz, 133Mhz, 166Mhz, 200Mhz and 266MHz.Megabyte (MB) and Gigabytes (GB) measure the size of DDR SD-RAM. They vary in size from 256mb-2Gb. The common sizes are 512mb, 1Gb and 2Gb. DDR SDRAM and DDR2 SDRAM have both increased the speed and size even further and they are similar prices so if possible go for DDR2 or DDR3.
7 SDRAMSDRAM or SDR SDRAM is a type of computer memory. SDR SDRAM stands for: Single DataRate Synchronous Dynamic Random Access Memory. So what does that mean? SDRAM SpecificationsSDRAM or SDR (Single Data Rate) SD-RAM can accept one command and transfer one piece of data per clock cycle. Typical clock speeds were 66Mhz, 100Mhz and 133MHz and for more money 150Mhz.Megabyte (MB) size in SDR SD-RAM varies from 8mb-512mb. The common sizes were 32mb, 64mb and 128mb. 256mb and 512mb sticks can be purchased for a little bit more. However, SD-RAM is no longer made so it has become more and more expensive to buy second hand. DDR and DDR2 RAM which are both a lot faster and better can be bought at a cheaper price.
9 Motherboards Everything in the computer connects to the motherboard. The Power Supply powers up the motherboard, the CPU, Memory, Hard Drives, are all connected to the motherboard.In recent motherboards, the sound cards and even the network cards are built into the motherboard making it unnecessary to purchase additional cards.However, built in components makes upgrading components difficult.The chipset is the most important component of a motherboard and it determines the capabilities and features .Motherboard’s can come with different options such as more expansion slots, Wi-Fi or a 1394 connection.
10 Central Processing Unit (CPU) The CPU is the “brain” of a computer.CPU speed is measured in hertz.Previously, measured in megahertz – one million cycles per secondToday, measured in gigahertz – one billion cycles per secondThe higher the amount of hertz the greater amounts of cycles can be completed and more information will be processed.Faster processors create more heat which means fans have to be upgraded.The CPU is placed in the CPU socket and forms an electrical interface with the motherboard.Regardless of the RAM or Hard Drive the CPU decides what and how fast programs will run on the computer.Modern processors have millions of transistors placed onto the little square which is called a die. The CPU is responsible for processing codes and instructions through to the motherboard which sends the information through to the graphics card where it then travels to your monitor and then appears on your screen.Intel released the first CPU processor which was the 4004 in the year of It ran at 740kHz (740,000 hertz) compared to the more modern computers that can run up to 3Ghz (3,000,000,000 hertz).
11 Hard Drive What does a Hard Drive do? The hard drive is a permanent storage device.Without the Hard Drive the computer would not be able to load the operating system.Hard Drives are measured in Gigabytes (one billion bytes).A computer hard drive is the place where computer data is stored. A HDD (Hard Disk Drive) is generally referred to as the secondary computer storage device, as the RAM (Random Access Memory) is the primary.Data that is stored on the RAM is volatile meaning when the computer is shut down then the information will be lost.A hard drive is a permanent storage device, so even when the computer is turned off the information will still be there.
12 How does a Hard Drive work? A hard drive uses circular platters to store data which are kept in pristine condition and are very good mirrors.If you open a hard drive case, the air will contaminate the platters and it is unlikely that it would work again.The actuator arm runs between the platters reading the information in 1's and 0's (BINARY). The head of this arm reads data even when the disk is running at 7200rpms (a common hard drive speed).This means that the platter is doing 7200 rounds per minute.More recent computer hard drives can now do up to 15,000rpms.As the platters go round and round the head reads it and processes the information which then proceeds to the connector which connects to the computer.
13 Hard Drive Specifications External or Internal?All the hard drives that are inside a computer are called internal hard drives.An External Hard Drive sits outside the computer and is connected to the computer through USB, Firewire or eSata.External drives are very useful for backing up your computer and for transferring files to two locations.External drives are also very portable.Hard Drive CapacityA computer hard drive is measured in Gigabytes. Different files take more space. Video files and pictures take up a lot of room, but simple text files take next to nothing. The operating system and program files take up space as well.Hard drive capacities vary between 1Gb (or less) to 2Tb (maybe even bigger).Hard Drive ManufacturersWestern DigitalSeagateSamsungIomegaHitachi
15 It is very important to back up your hard drive It is very important to back up your hard drive! Do not learn the hard way!
16 Common Hard Drive Specs. Which technology is right for me? 5,400 RPM hard drive disk (HDD) 7,200 RPM hard drive disk (HDD)Solid State Drive (Offered only on select systems only)PerformanceBasicFaster, quieter and more durable than standard hard drivesCapacity in Gigabytes (GB)250, 320, 500, and 640250, 320, 500, and 750128, 256 and 512DurabilityStandardStandard Highly Shock Resistant
17 Hard Drive ConnectorsThere are currently several types of connector cables in a common hard drive.IDE Ribbon CableSCSI CableSATA CableUSB – Universal Serial Bus
18 CD/DVD Drives or Optical Drive CD/DVD Drives are another storage device in a computer. CD Drives are used to read CD's with information on them such as an operating system, programs or data files.CD-RW and DVD-RW write data to blank disks.CD Drives are measured by their read and write speeds. 8x, 16x, 24xDrives take up a lot of space and small flash drives may make them obsolete.
19 Video CardsA video card is another compulsory component in a computer.Information goes into the video card and then is transmitted to the monitor where the information is displayed.Some motherboards have the graphics card built in, but the majority need a separate card that plugs into the motherboard.Video cards that are built into the motherboard make upgrading more difficult.
20 Sound CardA sound card is another extra that can be added to your computer.A sound card translates signals into sounds that can be played back through speakers.Many motherboards have a sound card incorporated in the motherboard, but for those that don't it is possible to get one.
21 Monitors Without a display or monitor… What is the point? The computer monitor connects to the graphics card and it displays a picture on the screen.Computer monitors come in different types:CRT (Cathode Ray Tube) which are block monitors.LCD (Liquid Crystal Display) which are very thin.LEDs (Light Emitting Diodes)Touch screen monitors are now also available.
22 Network CardA Computer Network Card or a LAN (Local Area Network) card required to connect your computer to different devices, the internet and WIFI.LAN ports are often incorporated on the motherboard.There are wireless network cards, USB network adapters, typical network cards and more.A network card is a piece of computer hardware, that is designed to allow computers to communicate over a network.
23 Modem A modem offers us access to the internet. The term modem means 'modulator-demodulator' – it modulates an analogue carrier signal to encode digital information and demodulates the signal to decode the information.In its modern form, wireless modems, which are examined in part three of this guide, convert digital data into radio signals and back.Originally modems had speeds of around 300bps and this was maintained until 1983 when 1200bps modems were introduced. However, by kbps became the standard.However, the limit to this technology was the 56k modem.In 1999 modems emerged with theoretical speeds of up to 8Mbps. Now even faster up to 50Mbps.A wireless router is usually added to a modem to broadcast WIFI broadband access over a LAN.Modem routers are as the name suggests routers with modems built-in. Excellent - you can get rid of one of those boxes and save power at the same time!
25 Wireless RouterDial up is dead and now we all have routers with a couple of LAN ports, and one or more antennas for WIFI. A router performs three main functions:The router - It is a clever receptionist that redirects data to whatever device is requested it.Always have a password on a secure network.A network switch – The router splits a single network usually four times so that different devices can access the network. Desktop, laptop, TV, IPad, IPhone etc.Make sure your router has a gigabit switch which will make it much faster and not the old 100 mbit.The wireless access point – This function really does the same thing as the switch but does so wirelessly.Most new routers have a “wireless-n” (802.11n) access point. This is much better over the older “g” standard. Look for “dual band” for the absolute best possible speeds.“n” may not be compatible on some devices.
26 Other components to consider… All-in-OnePrinterCopierFaxScannerWebcamOperating SystemWindowsMacSpeakers – SoundSync to TVApple TV is coming…
27 ReferencesIntel Corporation (2012). Introduction to Computers. Retrieved February 01, 2012 fromComputer Hardware Explained ( ) Understand these Computer Hardware Terms? Retrieved February 01, 2012 fromViewSonic Corporation ( ) VX2250wm-LED. Retrieved February 04, 2012 fromMoneysupermarket.com Ltd (2010). Guide to broadband hardware. Retrieved February 05, 2012 fromWhite Rabbit Ltd (2009). Wireless Router Types - Broadband vs Modem Routers. Retrieved February 05, 2012 fromRoytank.com (2011). Wireless routers explained. Retrieved February 05, 2012 from