PC Support & RepairChapter 1Intro to the Personal Computer

Objectives• After completing this chapter, you will meet these

objectives:▫Explain IT industry certifications. ▫Describe a computer system. ▫ Identify the names, purposes, and characteristics of:

Cases and power supplies. Internal components. Ports and cables. Input devices. Output devices.

▫Explain system resources and their purposes.

A+ Certification?•What is it?▫Describe the cert, tests, jobs, etc.

Computer System•What does it consist of?

Case•Form factor▫Desktop or tower▫Other names: chassis, box

•Protects internal components•Case fans keep equipment cool•Case grounds equipment

How to Choose a Case•Motherboard must fit it•Components you need must fit in it•Power Supply connection & rating• Looks, lights, etc• LED status lights•Venting▫Some have many vents for air flow

Power Supplies•Converts AC (wall) to DC (computer)▫DC is lower voltage

•Rated in Watts▫250-650 watts avg.▫Add up components▫Get more than you need

•What does a UPS do?

Power Supplies•What’s this?

Component Connectors•Keyed▫Fits one way only

•Color Cables & Power▫Yellow +12v▫Blue -12v▫Orange 3.3v▫Red +5v▫White -5v▫Black 0v GROUND

Power Supply to Motherboard•Current: 20 or 24 pin

•Older: P8 & P9▫Could plug in

wrong & fry MB

Molex Connector•CD/DVD & HD

•4 pin

•Only fits one way

Berg Connector•Floppy Drive•AGP Cards•For low power items

Power Supplies•What’s this?

•NEVER OPEN!!

•CAPACITORSHOLD A CHARGEFOR A LONGTIME!!

Project•Power Supply Handout▫Identify connectors▫Answer questions

•Find a power supply Handout▫Use the calculator

Motherboards• Large circuit board▫AKA system board or backplane▫Buses to pass data

•Form Factor▫Size & shape

AT Form Factor- OLD•Old desktops

•P8 & P9

•Too big

•Power-switched

•Was also Baby AT

ATX Form Factor- CURRENT•Current•Smaller▫Mini ATX▫Micro ATX

•20-pin PS connector• Layout better•No OFF switch

BTX Form Factor- CURRENT•2003

•Better airflow

•7 expansion slots

Motherboards & Chipsets•Controls how hardware interacts with CPU & MB▫Sets max amount of memory that can be installed▫Defines type of connectors on MB

•Northbridge▫RAM, Video, CPU

•Southbridge▫Hard drives, sound card,

USB ports, and other I/O ports

Project•Compare/contrast Motherboards

Review•What determines how much memory can be

installed on a motherboard?▫Chipset

•What does the Northbridge chipset control?▫Access to RAM, Video Card, CPU

•What does the Southbridge chipset control?▫HD, USB, Sound Card, I/O ports

•AT or ATX…Which is a current standard?▫ATX

Review•Other than ATX, what is another current motherboard

form factor?▫BTX

•Which of these would determine by the form factor? SELECT 2▫Color, Size, How much memory it can take, shape

•How many pin PS connector is on today’s MB?▫20

•Older AT MB connectors included what two?▫P8 & P9

CPU• Intel & AMD•Cycles per second▫MHz (millions), GHz (billions)

•Fits certain socket or slot▫Pins insert into socket with ZIF▫Newer CPU has no pins

•Many types of sockets▫Fit certain CPU, see chart

• Look at slide 1.4.2

CPU•Executes instructions•While processing data, next set of instructions are

store in cache memory•Two architectures (how completes instructions)▫Reduced Instruction Set Computer (RISC)

Small set of instructions designed to execute rapidly Old Apple CPUs

▫Complex Instruction Set Computer (CISC) Broad set of instructions in fewer steps per operation Intel & AMD

CPU• Front Side Bus▫Amount of data CPU can process▫32 or 64-bit

•Overclocking▫Speeding up CPU▫Could damage it

• Throttling▫Slowing down CPU

•Multi-core▫More than one core on a single chip▫Triple-core is a quad with one core disabled

Cooling Systems•Stay cool▫Heat will make it run

slower & damage it•Case fan•Heat sink & fan for CPU•Graphics card can have

fans for their GPU•Water-cooling

ROM•On MB• Instructions for boot & load OS•Non-volatile•Can’t modify/erase normally•ROM- info stored when made OLD•PROM- info stored after made OLD•EPROM- info stored after made; erased with UV light•EEPROM- can be erased/rewritten on board (flash)

RAM•Temp & volatile

•SRAM used for cache

•SDRAM

•DDR3 SDRAM▫Faster than DDR2▫Less power & heat

Memory Modules•SIMM▫30 or 72 pin

•DIMM▫168 pin SDRAM▫184 pin DDR▫240 pin DDR2

•SODIMM▫Laptops▫72 or 144 pin

FalseFalse

Memory Types & Speeds

Cache Memory•SRAM•CPU gets faster access to data

• L1▫Built into CPU

• L2 ***▫Next to CPU

• L3▫Next to CPU▫Used with high end CPU

Memory Error Checking•Non parity ***▫Kind used today▫No error checking

•Parity▫One bit checks for errors

•ECC▫Server▫Can detect multiple bit errors & correct them

Project•Research types of RAM•CPU cache

Adapter Cards•Name & ID different cards

•PCI 32 or 64 bit

•AGP 32 bit video

•PCIe replacing AGP

• ISA OLD 8 or 16 bit

Motherboard Slots

Floppy Drive•Magnetic storage•720KB OLD•1.44MB•A:

Hard Drive•Magnetic storage▫Spinning platters

•C:•GB•RPM

•SSD▫No moving parts▫Flash▫Faster access, low power

Optical Drive•CD, DVD, BD

•CD= 700MB

•DVD= 4.3GB single layer▫8.5GB dual layer

•BD= 25GB single layer▫50GB dual layer

Drive Interfaces• IDE OLDER 40 pin connector•EIDE OLDER 40 pin connector▫For drives bigger than 512MB▫40/80 conductors in wire

•SATA 7 pin connector•eSATA EXTERNAL•SCSI▫Can connect up to 15 drives▫50, 68 or 80 pin connector

RAID•Stores data across many hard drives▫Backup

•Parity –Detect data errors•Striping –Writes data across multiple drives•Mirroring –Storing duplicate data to a second drive

•RAID 1 mirroring (full redundancy)•RAID 5 striping

Project•Worksheet 1.4.7

•Extra Activity Handout

Ports•Name ‘em…•Serial▫9 pin▫Transmits one bit at a time SLOW!

•USB▫127 devices per port (using hubs)▫1.1= 12Mbps▫2.0= 480Mbps▫3.0= up to 4.8Gbps

Ports•Firewire▫Supports up to 63 devices per port▫IEEE1394a up to 400Mbps, 4 or 6 pin

•Parallel▫DB25, printer side is Centronics 36 pin▫IEEE1284▫8 bits at a time

Ports•SCSI▫End point in chain must be terminated

•Network▫RJ45▫Fast Ethernet is 100Mbps▫Gigabit is 1000Mbps▫328ft or 100m MAX cable length

Ports•PS/2▫6 pin female

•Audio▫In, out, MIC, S/PDIF, TosLink,

MIDI •Video▫VGA, DVI, HDMI, S-Video, Component

Input Devices•Data goes into the computer•Name some input devices

•What is a KVM?

Output Devices•From the computer to user•Name some output devices

• Let’s look at monitors

Displays•CRT• LCD•DLP

•Pixel•Dot Pitch▫Distance between pixels

•Native Resolution▫# of pixels▫1280 x 1024 (h x v)

Display Resolutions

Multiple Monitors on One Computer•Need two video ports▫Add another card (or two)

System Resources•Communication between CPU & other components• Interrupt Requests (IRQ) ▫Assigned automatically today▫Requests info from CPU▫16 IRQ’s (0-15)▫Each component has its own #

System Resources• Input/Output (I/O) Port Addresses▫Communicate between devices & software▫Over 65,000 ports▫

•Direct Memory Access (DMA)▫High-speed devices talk to memory▫Avoids bugging the CPU

End of Chapter Review

PC Support & RepairChapter 1Intro to the Personal Computer