Inside the Computer

Inside the Computer Integrated Technologies

Introduction • Computers are used by people around the world for various purposes • To most, the computer is merely a keyboard, mouse, monitor and tower connected together by many cables • Although the average user can tell you the function of each device above, few can tell you what is inside the tower and how the components inside work • We will devote this class to learning the components within a tower and how they interact with one another Inside the Computer

Preparing to Build • Tools • Hardware vs. Software • Hardware Tools • Do NOT use a Magnetic Screwdriver! • Power Screwdriver is fine • Multi-head Screwdrivers are great, provided they’re NOT magnetic • Flat Head Screwdriver (do NOT pry with them!) • Philips Screwdriver (usually No. 2 – smaller for notebooks) Inside the Computer

Hardware Tools Continued • Torx Screwdriver usually sizes T-10 and T-15 (especially for Compaq and Apple computers) You may need smaller ones for laptop computers • Needle-Nose Pliers • Flashlight • Dental Mirror • A container to put screws in so you don’t lose them • Compressed Air • More useful for cleaning older systems, but a good thing to have around Inside the Computer

Software Tools • Boot Device • To “Boot” means to start up a computer • Cold boot – start from power off • Warm boot – re-start from power on • A Boot device is any medium (Floppy Disk, CDROM, DVD, USB drive) that the computer can get its starting instructions from • Will hold on it the “kernel” of an operating system • The kernel of an operating system is the minimum set of instructions needed to get a computer to start up, recognize its different parts and perform minimal but key tasks • Tasks include • Formatting a hard drive • Writing more start-up instructions • Running programs from other devices (i.e. CD’s) • Check in the BIOS what type of devices the motherboard can use to boot from Inside the Computer

Software Tools Continued • Bootable Floppy Disk • Typically Windows 98 SE so it can handle large drives • Make sure it has a CD ROM driver loaded • Data reading/recovery utilities • Network capable floppy a good idea • Bootable CD ROM • Many systems no longer include floppies (especially laptops) • Same features as for a Floppy • Don’t just rely on an OS install CD, you most likely one that will allow you some data access • A “Live CD” (e.g. Knoppix – Linux and free, BartPE – Windows needs a Windows license, etc) • Bootable USB Drive • Not all motherboards will have a setting to boot from USB, so this is not as good an idea Inside the Computer

Software Tools Continued • There are many software packages that will examine the hardware, report its configuration and identify any errors they find • CheckIt Pro • QAPlus • Microsoft’s MSD (Microsoft Diagnostics) • http://www.majorgeeks.com has MANY tools that are both general and hardware/software specific that you may want to look at (ALWAYS beware of Internet downloads, especially ones designed to dig into a system’s hardware and software! Why?) Inside the Computer

Preventative Measures • Both you and the computer contain components that can easily be damaged, always be careful and keep safety in mind! • Don’t have loose cords lying around • Always put parts entirely on flat and stable surfaces, not stacked on each other! • Keep liquids and foods well away from all components Inside the Computer

Preventative Measures Continued • Don’t let yourself get distracted • Have a plan BEFORE you start to work • Tuck in or remove loose or hanging clothing (e.g. a tie) or hair • Be aware that there are MANY sharp edges and soldering bumps that can cut and nick your hands and fingers • Before you power a system on that you’ve worked on make sure all parts are “Seated” securely by gently and evenly pressing on all connectors and parts evenly into their sockets Inside the Computer

Electrostatic Discharge (ESD) • ESD occurs when two objects of dissimilar charge come in contact with one another • CPU and memory chips are extremely sensitive to ESD • 100 volts is enough to damage computer parts • You can generate 100 volts by just sitting in a chair • You can generate 3000 volts by shuffling your feet across a carpeted floor • You can SEE 10 000 volts get transferred Inside the Computer

Avoiding/Minimizing ESD • Try to avoid “dry” rooms • Keep relative humidity to around 50% where possible • Anti-static Wrist Straps • Plug into the round part of a wall plug or clip onto the round poll of an extension cord • Anti-static Mats • Drains excess charge away from any item coming in contact with it • Keep parts you are not using in Static Bags • Use an anti-static spray • Or, a spray with one part liquid fabric softener and one part water • Vendors will ship goods with anti-static foam, keep that around and use on the table-top • While working, keep part of your skin touching (grounded to) the metal case of the power supply that is plugged into a grounded outlet Inside the Computer

Components and Connectors • You will need to have an idea of what pieces you have, where they go in the system and what their purpose is • You will need to know how they connect and thus communicate with each other Inside the Computer

Case • Today, towers come in many cool shapes and designs • The basic purpose of the tower is to contain and protect the computers hardware components • Hardware components are mounted by plastic clips or by screws • The front of the tower contains panels that can be removed, thus exposing the “bays” • These bays are slots that hold devices such DVD/CD-ROM drives, floppy drives and other devices that need to have external access Inside the Computer

Motherboard • A motherboard allows all the parts of your computer to receive power and communicate with one another • The first motherboards held very few actual components and had only a processor and card slots • Today, motherboards boast a wide variety of built-in features, and they directly affect a computer's capabilities and potential for upgrades Inside the Computer

Motherboard (cont’d) • Most people physically interact with a motherboard on a daily basis and don’t even know it • If you have ever plugged in a printer, mouse, memory stick, joystick or any other device to your computer, chances are you plugged it into the motherboard • This is known as the “back” of the motherboard • Every place that you can plug a device into is called a port Inside the Computer

Motherboard (cont’d) • The inside of a motherboard controls all the hardware on your system • key motherboard components: • Bus • Processor Socket • Memory Socket • IDE/SCSI/RAID/SATA • PCI/AGP or Expansion Slots • This is where you plug in Expansion Cards which can give your computer extra functionality • E.g. game controller cards, Network cards, advanced video cards etc. • BIOS Chip Inside the Computer

Bus • The power and speed of computer components has increased at a steady rate since desktop computers were first developed decades ago • However, there is one element that often escapes notice - the bus • The bus is a channel or pathway between the components in a computer (i.e. CPU, RAM, Sound Card, … etc) • The best analogy for this is that if you have a 1000HP engine and a cheap transmission, you can't get all that power to the wheels • Today, the processors run so fast that most computers have two or more buses • It is important to know the bus speed when purchasing a motherboard Inside the Computer

BIOS Chip • On virtually every computer, the BIOS makes sure all the other chips, hard drives, ports and CPU function together • The BIOS software’s most important role is to load the operating system, since there are no instructions to the CPU at start-up • The BIOS provides these instructions • Some of the other common tasks that the BIOS performs include: • A power-on self-test (POST) for all of the different hardware components in the system to make sure everything is working properly • Activating other BIOS chips on different cards installed in the computer • Managing a collection of settings for the hard drives, clock, … etc • Whenever you turn on your computer, the first thing you see is the BIOS software doing its thing • On many machines, the BIOS displays text describing things like the amount of memory installed in your computer, the type of hard drive and so on Inside the Computer

BIOS Chip (cont’d) • To enter the BIOS Setup, you must press a certain key during the initial start-up sequence, usually Del or F1 key • Once in there, you may see some of the following options: • System Time/Date • Boot Sequence • Plug and Play • Mouse/Keyboard • Drive Configuration • Memory • Security • Power Management • Exit • Be very careful when making changes to setup as incorrect settings may keep your computer from booting Inside the Computer

Hard Drive & CD-ROM Power Floppy Drive Power Motherboard Power Power Supply • Of course any piece of electronics needs electricity • The computer gets its power via the power supply which converts 120V/220V AC to lower DC voltages, such as 3.3V, 5V and 12V • The 3.3V and 5V are typically used by digital circuits, while the 12V is used to run motors in disk drives and fans • Power supplies are measured in Watts • They also can get can get very hot so they come with a built-in fan Inside the Computer

Power Required Inside the Computer

CPU Intel 4004 Intel 8080 • The CPU, or microprocessor as it is also called, is the heart of any desktop computer, server or laptop • A computer may be using a Intel, AMD or G5 CPU, but they all do approximately the same thing in approximately the same way • The first microprocessor, introduced in 1971, was the Intel 4004 and it could only add and subtract 4-bit numbers • The first microprocessor to make it into a home computer, introduced in 1974, was the Intel 8080, and it could only add and subtract 8-bit numbers • Today’s microprocessor can process 64-bits at a time and are thousands of times faster • A CPU contains millions of transistors – think of them as switches that simply go on and off • The human hair is 100 Microns in width Inside the Computer

CPU (cont’d) • CPUs today are incredibly small but very complex in design • The CPUs job is to fetch, decode and execute instructions • Every CPU has a set of instructions that it can perform • Each instruction has a different meaning when loaded into the instruction register • A set of short words are defined to represent the different instructions • This collection of words is called the assembly language of the processor Inside the Computer

Processor Socket • In the early days of PC computers, all processors had the same set of pins that would connect the CPU to the motherboard, called the Pin Grid Array (PGA) so that any processor would fit into any motherboard • As CPUs advance, they need more and more pins, both to handle new features and to provide more and more power to the chip • Anyone who has a specific CPU in mind should select a motherboard based on that CPU, otherwise it will not fit Inside the Computer

Processor Socket (cont’d) Inside the Computer

Processor Socket (cont’d) • The processor socket serves two purposes: • Holds the CPU • Holds the CPU heat sink/fan • As the CPU executes commands, it can get extremely hot • As a result, a heat sink/fan is required to keep it cool • Failure to attach the heat sink/fan will cause the chip to go up in smoke, literally • DON’T separate the heat sink from the CPU unless you have the conductive silicon Inside the Computer

Memory • There are many types of memory: • RAM • ROM • Cache • Dynamic RAM • Static RAM • Flash memory • Memory Sticks • Virtual memory • Video memory • BIOS • Random access memory (RAM) is the most common form of computer memory • Technically any form of electronic storage is memory, but it is often used to describe temporary forms of storage Inside the Computer

Memory (cont’d) • RAM modules come in various sizes (pins), capacities (MB/GB), speeds (MHz) and types • Here are a few types of RAM used today: • SDRAM (Old and slow) • DDR SDRAM (Most common and fast) • RDRAM (Rare and very fast) • RAM is very fast since it is composed entirely of circuitry, unlike hard drives which are mechanical • Remember, RAM is temporary storage Inside the Computer

Memory Socket • Memory sockets hold and connect RAM modules to the motherboard • They provide a link to the bus so that the memory can communicate with other components on the motherboard • Today, motherboards have three or more memory sockets, thus allowing various configurations of RAM Inside the Computer

Memory Socket (cont’d) • Installing RAM is very easy, but a delicate affair • Before adding RAM to a motherboard, make sure it is the right size, capacity, speed and type • Often, adding more RAM to a computer can increase its performance Inside the Computer

Hard Drive • Nearly every computer and server contains one or more hard drives, while mainframes and supercomputers normally use hundreds of them • Hard drives magnetically store changing digital information into relatively permanent files, thus allowing computers the ability to remember things when the power goes out • A typical hard drive has a capacity between 80 and 320GB • There are two ways to measure the performance of a hard drive: • Data rate - The data rate is the number of bytes per second that the drive can deliver to the CPU (Normally between 5 and 40MB/s) • Seek time - The seek time is the amount of time between when the CPU requests a file and when the first byte of the file is sent to the CPU (Normally between 10 and 20 milliseconds) • The other important parameter is the capacity of the drive, which is the number of bytes it can hold Inside the Computer

Hard Drive (cont’d) • A hard drive is a sealed aluminium box with controller electronics attached to one side • The electronics control the read/write mechanism and the motor that spins the platters • The mechanical aspects of the drive are as follows: • The motor – Spins between 3600 to 7200rpm • The platters - Are manufactured to amazing tolerances and are mirror-smooth • The arm - Holds the read/write heads and is controlled by the mechanism in the upper-left corner • The mechanism that holds the arms can move the heads from the hub to the edge of the drive about 50 times per second • In order to increase the amount of information the drive can store, most hard drives have multiple platters and read/write heads Inside the Computer

Hard Drive (cont’d) • Data is stored on the surface of a platter in sectors and tracks • Tracks are concentric circles (yellow), and sectors (blue) are pie-shaped wedges on a track • A sector contains a fixed number of bytes • Sectors are often grouped together into clusters • The process of low-level formatting a drive establishes the tracks and starting/ending sectors on the platter • This process prepares the drive to hold blocks of bytes • High-level formatting then writes the file-storage structures, like the file-allocation table, into the sectors • This process prepares the drive to hold files Inside the Computer

IDE/SCSI/RAID/SATA • Most computers have one or more of the following storage devices: • Floppy drive • Hard drive • CD-ROM drive • Usually, these devices connect to the computer through an Integrated Drive Electronics (IDE) interface • These devices are connected via IDE cables • However, IDE is an old technology and there have been advancements to better its performance Inside the Computer

IDE/SCSI/RAID/SATA (cont’d) • The following are some technology enhancements that have been made: • SCSI – Faster and reliable • RAID – Allows for two hard drives to be connected in synch • SATA – Latest technology and is very fast • The above each have their own special cables, except RAID which still uses IDE Inside the Computer

Ribbon Cables • Each of IDE/SCSI/SATA have their own cables to fit into the connectors on the drives and the motherboards • These cables are called ribbon cables because of the way they look • Be careful when detaching and re-attaching the cables because pulling or pushing on an angle could bend or break pins on the motherboard and/or drive • Use tabs provided on the cables for pulling the cables out • Make sure the connectors are lined up flat to the controller on the motherboard before you push them into place • There are generally two numbered slots/controllers on the motherboard to plug these cables into • If you only need one cable make sure it is plugged into the slot with the lowest number Inside the Computer

Jumpers • When you have multiple IDE type devices that connect to the motherboard using the same cable you may have to set what are called “jumpers” one each drive to tell the motherboard which drive should take what “priority” on that cable. • There are 3 basic settings: • Master – the most important drive, if this cable is connected to the first connector on the motherboard then the Master drive is the one the computer will want to boot from. This is also called the Primary drive. • Slave – the less important drive, called the Secondary drive • Cable Select – indicates that the drive plugged in at the end of the cable is the Primary drive and that the drive plugged into the connector part way down the cable is the Secondary cable. Inside the Computer

Video Card • The images you see on your monitor are made of tiny dots called pixels • At most common resolution settings, a screen displays over a million pixels, and the computer has to decide what to do with every one in order to create an image • To do this, it needs a translator - something to take binary data from the CPU and turn it into a picture you can see • This translation takes place on the video card • A video card's job is demanding and complex, but its principles and components are easy to understand • To make a 3-D image, the video card first creates a wire frame out of straight lines and then fills in the remaining pixels • It also adds lighting, texture and color • For fast-paced games, the computer has to go through this process about sixty times per second Inside the Computer

Video Card (cont’d) OpenGL Rendering (Doom 3) • Like a motherboard, a video card houses a processor, RAM and BIOS chip • A video card's processor, called a Graphics Processing Unit (GPU), is similar to a computer's CPU except it is designed specifically for performing the complex mathematical and geometric calculations that are necessary for graphics rendering • Some of the fastest GPUs have more transistors than the average CPU and produces a lot of heat, so it is usually located under a heat sink or a fan • ATI and NVIDIA produce the vast majority of GPUs on the market, and both companies have developed their own enhancements for GPU performance • To improve image quality, the processors use: • Full scene anti aliasing (FSAA), which smoothes the edges of 3-D objects • Anisotropic filtering (AF), which makes images look crisper DirectX Rendering (Far Cry) Inside the Computer

PCI/AGP Slots • PCI slots are what connect your network card, sound card, … etc to the PCI bus • They are easy to install and support “Plug & Play” • Most motherboards provide four or more of these slots for any additional devices you may want to add Inside the Computer

PCI/AGP Slots (cont’d) • Today, computer software is very complex and demanding • This is especially true when dealing with graphical applications such as videos and gaming • As a result, the video card is used quite intensely and requires quick access to system resources • Video cards used to be connected to PCI slots, but are now connected to an Accelerated Graphics Port (AGP) slot • The AGP slot is given a special link to the CPU, thus bypassing most of the PCI bus • This slot is located by itself, above the PCI slots Inside the Computer

Inside the Computer