Ultimate Comtia A+ Certification Study Guide

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[edit section] Introduction & Acknowledgements

This is a ProProfs.com community member supported Comptia A+ Study Guide, originally created by cbrzana. Cbrzana created this for his own study and then shared it on the forum for everyone's benefit. The chapters of the guide are modeled after the popular and recommended Mike Meyers All-In-One book.The guide is however not a replacement for the book and should be used in conjunction with the book (visit amazon.com for the book).

Thanks Cbrzana for all the hard work that went into producing this guide and for sharing it with everyone . The study guide is maintained by entire ProProfs community. Contributions and enhancements are most welcome!

Comments and feedback thread is also available for your valuable suggestions and comments. You can also download a MS word version of the original guide as download. Feel free to upload your enhancements there or preferably directly edit the wiki version.

[edit section] Chapter 2: The Visible PC

CPU: Measure potential performance with clock speed (Hertz). Manufacturers produce same make and model processor with different clock speeds.

PGA: Pin Grid Array, predominant

SEC: Single Edge Cartridge, no longer produced

Motherboard: provide sockets for microprocessor, RAM, power, connectors for floppy drives/hard drives, and external devices.

-Certain types of motherboards require a case designed for that type.

Power Supply: Takes standard 115-volt AC power and converts it into ±12-volt, ±5-volt, and +3.3-volt DC power.

Hard Drives: Two different industry standards.

EIDE: Enhanced Integrated Drive Electronics, 95% of PCs use this. Each controller holds a ribbon cable capable of supporting two hard drives.

SCSI: Small Computer System Interface, faster, more expensive. Very few motherboards have SCSI controllers, creates need for SCSI controller card (SCSI host adapter). SCSI supports many different types of devices.

Different Types of Connectors

Pins = Male, Sockets = Female

DB Connectors: Slight D shape, "Databus Connectors", can have from 9 - 37 pins

DIN Connectors: Two sizes, DIN (5-pin) and mini-DIN (6-pin), sockets always female, circular-shape

Centronics Connectors: Similar D-shape, use large central tab, covered w/ contacts rather than pins, distinctive "wire wings" that lock socket in place. Always female, seen mainly on older printers.

RJ (Registered Jack) Connectors: Two types, RJ-11 (phone jack/modem) - square shaped and RJ-45 (network cabling) - rectangular

BNC Connectors: Coaxial/coax connectors, similar to connectors on TV, twist-type connection.

USB: Hot-swappable, allows insert/removal without need to restart computer, Daisy-chaining, up to 127 USB devices.

Firewire Connectors: IEEE 1394, high data rate (100-400 Mbps), 6-wire cable supplies power to external device, 4-pin version needs separate power supply, no longer than 5 meters in length.

Serial Ports: 25-pin or 9-pin male DB port.

Parallel Port: Use a 25-pin female DB connector.

Both Keyboards and Mouse may use the PS/2 style mini-DIN connector

[edit section] Chapter 3: Microprocessors

CPU: terms microprocessor and central processing unit are interchangeable. Made up of millions of transistors.

External Data Bus (EDB): Allows channel for flow of data between the CPU and RAM.

Registers: CPU's "worktables", provide memory to perform equations

Commands go in high-order bits (8,7,6,5) and data goes in low-order(4-1)

Physically are circuits that hold charges

Clock Wire: A charge on the clock wire tells the CPU more info is waiting to be processed.

-A single charge to the clock wire is a clock cycle.

		CPU needs at least 2 clock cycles to act on a command.
		-Maximum # of clock cycles a CPU can handle is its clock speed
		-System crystal determines the speed at which a CPU operates (Metronome)
		Overclocking is when the crystal pushes the CPU faster than it can go.

Northbridge: "RAM-grabbing" device

Address Bus: Allows communication between CPU and Northbridge

Intel Processors: Lower-end = Celeron, Typical = Pentium, Higher-end = Xeon

AMD - Advanced Micro Devices, 30-40% of the market.

Starting w/ Pentium 2, AMD no longer compatible

To use AMD CPU, must have AMD compatible motherboard (Same with Intel)

Two types of CPU packages

PGA: Pin Grid Array, fell out of favor in Pentium 2, but once again predominant. Square shape, hundreds of pins.

-3 common variations: Ceramic (CPGA), Plastic (PPGA), and Flip-Chip (soldered to a small board (FC-PGA)

To easily remove chip, developed Zero Insertion Force (ZIF) sockets, identified by removal arm. Called each type of ZIF Socket "Socket 1, 2, 3, …."

Pentium: Socket 4, 5, and 7(321 pins). ? eventually named sockets according to how many pins they had.

-First processor to have 32-bit registers, ran at 300Mhz

-Special registers that track all running programs

-Wider address bus

AMD: Only one type of socket, the 462-pin Socket A

Pentium II: ditched PGA package, developed the:

SEC: Single Edge Cartridge, snapped into a special slot on motherboard called Slot 1.

? two variations, SEC2 had front cover, SEP no cover

AMD: Used "Slot A"

Cache: Set aside data used in the past for fast storage area. (Use while system refreshes)

Disk cache: Moving data between mass storage and RAM

RAM cache: Moving data between RAM and the CPU. Backlog of commands which are executed during wait state

Types of RAM used for RAM cache

DRAM (Dynamic RAM): Fast, cheap, must be refreshed (charge capacitors) ? volatile

?Northbridge tells refresh circuitry on DRAM when to refresh. (wait states)

SRAM (Static RAM): Uses "flip-flops" rather than capacitors, much faster, very expensive, no refresh needed

External Cache (64KB to 1 MB) larger than Internal Cache

(16 KB)

Pentium Pro: built-on second cache, so term internal/external lose meaning. Instead, use L1, L2, L3.
Pipeline: the series of steps the CPU needs to process a command.

Dual Pipelining: enabling more than one command of certain types to be processed at a time. (Laundry analogy)

Clock Multiplier: Takes the incoming clock signal and multiplies it inside the CPU to let the CPU run faster. ? Allows CPU to go faster than the rest of the circuits on the motherboard.

? creates two CPU speeds -- slow external speed, fast internal speed

CPUID: CPU Identifier, allows speed and multiplier to be set automatically.

Voltage Regulators on motherboards allow lower voltages in CPU's (prevent overheating) -- since many varieties existed, needed an easier way which is:

Voltage Regulator Modules (VRM): card that comes w/ CPU contained voltage regulators specific to that CPU (installed in special VRM socket)

*Note: VRM now outdated, CPU's now tell motherboard automatically.

Dynamic Processing: While in wait-state, processor looked at code to see if anything could be processed out or order to save time.

Frontside Bus: Address Bus and External Data Bus, lumped with CPU, Northbridge, and RAM

Backside Bus: Connection between the CPU and the L2 cache

All Pentium and better processors have 64-bit databus and 32-bit address bus.

MMX: Multimedia Extensions, four new registers and 57 new commands, move/manipulate large chunks of data, used for graphical applications.

Split Voltage: CPUs could run lower than 3.3 volts, but to communicate with other chips on the motherboard, needed two different voltages to operate properly.

Difference in Itanium and Opteron 64-bit processors: One gives choice of using 64 or 32 bit code, the other doesn't (Intel doesn't allow it, AMD does)

CPU	Gen	External Speed	Internal Speed	Multiplier Range	L1	L2	L3	Package	Sockets Used
Pentium	5^th	50-66 MHz	60-200 MHz	1-3x	16KB	No	No	PGA	4,5
Pentium Pro	6^th	60-66 MHz	166-200 MHz	2.5-3x	16KB	256 KB, 512KB, 1 MB	No	PGA	8
Pentium II	6^th	66-100 MHz	233-450 MHz	3.5-4.5x	32 KB	512 KB	No	SEC	Slot 1
AMD K6	6^th	66-100 MHz	200-550 MHz	3-5.5x	32 KB 64 KB	No(K6-2) 256 KB	No	PGA	7
Pentium II (Celeron)	6^th	66 MHz	266-700 MHz	4-10.5x	32KB	128 KB (later versions)	No	SEP, PGA	1, Socket 370
Pentium III	6^th	100-133 MHz	450 MHz-1.26GHz	4-10x	32 KB	256 KB or 512 KB	No	SEC-2, PGA	1, Socket 370
Pentium III Celeron	6^th	66-100 MHz	533-700 MHz	8-11.5x	32 KB	128 KB	No	PGA	Socket 370
Classic AMD	6^th	100 MHz	500 MHz - 1 GHz	5-10x	128 KB	512 KB	No	SEC	Slot A
AMD Thunderbird	6^th	100-133 MHz	650 MHz - 1.4 GHz	3.5-14x	128 KB	256 KB	No	PGA	Socket A
AMD Duron	6^th	100 MHz	600 MHz-1.3 GHz	3.5 - 14x	128 KB	64 KB	No	PGA	Socket A
Pentium 4	7^th	100 MHz-200 MHz (quad pumped)	1.3-3.2 GHz	13-23x	128 KB	256 KB, 512 KB	No	423 PGA, 478 PGA	423, 478
Athlon XP	7^th	133 MHz, 166 MHz	1.3 GHz-2.16 GHz	13-16.5x	128 KB	256 KB, 512 KB	No	462 PGA	Socket A

Xeons used, generally, if more than one processor is to be used (in sets of 2, 4, or 8)

-Xeon uses slot 2

Mobile Processors

Mobile processors denoted by word "mobile" or letter "M" in its name.

Ex) Mobile AMD Duron, Athlon XP-M

Mobile needs to be smaller, use less power, and run cooler than their desktop counterpart.

1) Smaller:

Tape Carrier Package: (CPU without the packaging)

Mobile module: Entire PC on a small card.

2) Use Less Power/Run Cooler:

Runs at lower voltage than desktops, which leads to lower speeds.

-(75% of desktop power)

System Management Mode(SMM) allows CPU to turn off devices.

Intel's Speedstep/AMD's PowerNow!: allows CPUs to slow down during low demand times, or if the CPU detects that it is too hot.

Concerns When Installing CPU

1) Socket or Slot

Some adapters available, called slockets

Can never install an AMD processor on Intel motherboard, or vice versa

2) OEM versus Retail-boxed CPUs

-OEM, you need to find the correct cooling fan

-Retail, avoid risk of illegal CPU

3) Check to See if any Jumpers/Switches need adjustment.

-Many motherboards have no jumpers or switches

4) For Slot 1/ Slot A CPU

Install CPU Mount

Add small amount of heat sink compound before mounting the fan.

Slide straight down into the slot.

Plug in CPU fan's power.

5) For PGA-Type CPU

Don't touch the pins on the CPU

Line up orientation notches

Lift ZIF arm, align CPU, and should drop right in.

Make sure CPU is all the way in, snap down ZIF arm

Add heat sink compound -if already on fan, remove tape that covers it.

Attach fan, usually needs more force than you may think.

Connect fan power, marked on most motherboards.

6) Test the CPU

Make sure system has power, make sure CPU firmly pressed down, double-check jumper settings.

[edit section] Chapter 4: RAM

RAM -Random Access Memory, programs from mass storage copied into RAM and then run.

DIPPS (Dual Inline Pin Package): two rows of pins extending from either side. Susceptible to bend/break of pins, one or more rows of eight sockets ? primarily all rows needed to be populated or unpopulated.

? Led to manufacturers soldering the RAM onto small boards (sticks)

30-Pin SIPPs (Single Inline Pin Package):installing and removing RAM much simpler

? still susceptible to bending/breaking pins

30-Pin SIMMs (Single Inline Memory Modules):No protruding pins, virtually impossible to install incorrectly. Electronically identical to 30-Pin SIPPS. RAM chip number varied greatly.

RIMMs - RIMM is not an acronym and is a trademark of Rambus incorporated for the Direct Rambus or DRAM modules. RIMM is a type of computer memory that resembles DIMMs; however, it is 184-pin and is available with built in ECC support and Non-ECC at speeds up to 800MHz. RIMM modules are commonly used on the Intel Pentium 4 motherboards. Parity used for error detection, manifested through an extra 1-bit chip in the row.

? Non parity RAM would not work in system that required Parity RAM (odd number chips = parity RAM)

Earlier RAM, Northbridge had to wait for DRAM to retrieve data ? Fast Page Mode (FPM) RAM. Described in nanoseconds.

72-Pin SIMMs: larger capacities, faster access speed (60-80 ns). 32-bits wide.

? x32 described non-parity, x36 described parity

Banks: each bank of RAM can deliver data the full width of the data bus

DIMM (Dual Inline Memory Module): to keep pace with CPU and bus developments, RAM made to transfer 64-bit chunks

?most common varieties are 168 and 184-pin.

Laptop = '''68, 144, 172-pin Micro-DIMM

72,144,200-pin Small Outline DIMM (SO DIMM)

'''*72-pin SO DIMM only one to not deliver 64 bits from a single stick.

EDO (Extended Data Out) RAM: needs to be refreshed much less than FPM DRAM.

? 72-pin SIMM or 168-pin/SO *486s w/ 72-pin couldn't use

SDRAM (Synchronous DRAM):tied to the system clock, Northbridge knows when the data is ready to be grabbed from SDRAM. Quite a bit faster than DRAM, pipelines instructions from Northbridge so it is ready as soon as Northbridge takes previous command.

? doesn't have a access speed, but rather, a clock speed (66,75,83,100,133 MHz)

-- speed must be faster than or equal to motherboard speed.

PC100/133 Specifications: 100-MHz or 133-MHz RAM, unique chip called serial presence detect(SPD) ? provides system w/ size, speed, and other technical info.

ECC (Error Correction Code) DRAM:any size RAM can use, but most common in 168-pin DIMMs. Need motherboard designed to use ECC. Rarely seen in standard home/office desktop.

Registered DRAM: seen in servers/high-end workstations, facilitates high-volume data flow in/out of RAM. Has logic circuits (registers).

Double-Pumping: double to system bus speed, two bits of data with every clock cycle.

RDRAM (Rambus DRAM): aka RIMM,handle speeds up to 800 MHz, industry support poor due to high price/development delays. Come in 184-pin for desktops, 160-pin SO-RIMM for laptops. Can't install RIMM on DIMM.

? labeled as "PC" + Speed in MHz

- NOTES: RIMMS run very hot, require heat dissipation device (heat spreader) All RIMM slots must be populated. Unused pairs of slots use passive device called Continuity RIMM (CRIMM). Must also be installed in pairs, since it employs a dual-channel architecture (same speed/capacity).**

DDR SDRAM (Double Data Rate SDRAM):making two processes for every clock cycle. Comes in 184-pin DIMMs for desktops, 200-pin SO-DIMMs or 172-pin micro-DIMMs. Run at 200, 266, 333, or 444 MHz.

? labeled as "PC" + (8 * MHz speed) Ex = PC 3200 (8 * 400 MHz)

? also labeled "DDR" + MHz speed

Double-Sided SIMMs/DIMMs:two sticks of RAM soldered onto one board.

Installing RAM

1) Determine if insufficient RAM is the cause of system problems.

-general system sluggishness, excessive hard drive accessing.

-excessive hard disk access to the swap file

-ctrl+alt+delete, Performance Tab shows Page File (swap file)

2) Pick the proper RAM for the system.

-Windows-pause/break on newer keyboards to see current RAM

- open case, see how many RAM sticks already installed/open.

- shoot for uniformity in RAM (mixing destabilizes many systems)

- okay to use RAM faster than motherboard, no improvement though

3) Use good installation practices. ? store in antistatic packaging

SIMMs:have a notch on one side, insert at 45 degree angle. Push upright until holding clamps are secured on both sides. Should line up nicely/evenly.

DIMMs/RIMMs: Swing tabs down from upright position, good hard push down, tabs should close.

SO-DIMMs in Laptops:Usually requires removing a panel/lifting up the keyboard. Slide pins into position, snap the SO-DIMM down into retaining clips.

Troubleshooting RAM

Parity error at xxxx:xxxxx ? write down Hexideciaml value, if appears at same location, bad RAM stick

? power supply sometimes source of problem

"Replace and Pray" method ?swap in and out RAM sticks.

[edit section] Chapter 5: BIOS and CMOS

Southbridge: Handles all the inputs and outputs to the devices in the PC

? "chipset" describes Northbridge/Southbridge chips on the motherboard

External Data Bus ? Northbridge ? External Data Bus ? Southbridge ? I/O devices

Address bus goes to every device in a modern PC to enable CPU to send commands through chipset to every device in the PC.

Keyboard Controller: now integrated into Southbridge, uses own codebook to determine which key is pressed.

ROM (Read-Only Memory) Chip: Place where keyboard controller (and other programs) stored, stores exactly like RAM (8-bit wide "spreadsheet"), nonvolatile, once a program stored on one, it can't be changed.

CPU ? ROM Chip ? Specified controller/program

BIOS (Basic Input-Output Services): hundreds of little communication programs stored collectively on the ROM chip. Each tiny program called a service. Hold up to 2 MB.

? programs stored on ROM chips known as firmware

-ROM BIOS address reserved (last 65,536 addresses)

CMOS (Complementary Metal-Oxide Semiconductor): a separate memory chip that stores information that describes specific device parameters.

? does not store programs, store data that is read by BIOS.

? clock, gives current date/time

? usually store around 64KB of data

CMOS Setup Program: 3 big companies write about 99% of BIOS:

1. American Megatrends

2. Award Software

3. Phoenix Technologies

Always possible to access system's CMOS setup program at boot.

? Different key combinations for different BIOS vendor

CMOS Setup Utility

1. Standard CMOS Features - change floppy/hard drive setting, adjust date/time.

2. CPU Soft Menu - enables you to set the voltage/multiplier settings on the motherboard.

3. Advanced BIOS Features - Use this screen to select the boot options.

4. Advanced Chipset Features - Deals w/ low-level chipset functions, AVOID.

5. Integrated Peripherals - Used often, enables you to configure the onboard ports (serial/parallel ports)

6. Power Management Setup - Control how and when devices turn on/off to conserve power.

7. PnP/PCI Configurations - deals with Plug and Play devices, set aside interrupt requests (IRQs).

Reasons for losing CMOS Data in the old days:

Dead onboard battery
touching the motherboard
dirt on the motherboard
faulty power supplies
chip creep - caused by heating/cooling of chip out of mounts.

Flash ROM: stores the system BIOS and CMOS ? SRAM Chip (CMOS): stores BIOS setting that are configured using the setup program.

? Flash ROM can be reprogrammed to update their contents.

ex) A:\> aw athxpt2.bin ? updates ROM from the command line

Programmable ROM Variants

EPROM (Erasable Programmable ROM) - update = send motherboard to manufacturer
EEPROM (Electrically Erasable Programmable ROM) - update = boot to floppy, run program
Flash ROM - faster at rewriting the chip

SRAM chip called NVRAM (Non-Volatile RAM) - relies on battery backup (coin battery) ? pry with screwdriver, double check voltage/amperage beforehand

Option ROM: ROM included on the device itself. Not seen often except for video cards (for internal functions)

Device Drivers: file stored in the PC's hard drive that contains commands necessary to talk to device. Loaded into RAM after the operating systems starts them.

Files that contain list of device drivers

1. CONFIG.SYS - resides in root directory in C: drive in Windows 9.x. To edit, run SYSEDIT.

2. SYSTEM.INI - allows driver to run under 32-bit environment. Every version of windows still uses this (9x/ME systems require it). Text file broken into sections. Drivers distinguished by "device ="

3. Registry - Every configuration setting in every version of Windows is stored in the Registry (including device driver). Complex binary file, rarely edit directly, use control panel/device manager.

REGEDIT (Windows 9x/Me) and REGEDT32 (NT, 2000, XP)

'Control Panel '? Start | Control Panel (XP) or Start | Settings | Control Panel

'Device Manager '? Open system applet in control panel, device manager tab

OR (2000/Xp) Open system applet, Hardware Tab, Device Manager

Power-On Self Test

When computer starts up, special program stored on the ROM chip (POST) checks out the system. This happens by POST sending command to all devices that get BIOS support to "check yourself out", devices perform own internal diagnostics.

Output = Tell PC user an error exists (beep code/ text messages).

? long beep followed by 2 short beeps is a Video Card Failure

? beeps for overheating systems, failed/bad RAM as well

301 = Keyboard Error 201 = Memory Error 1101 = Serial Card Error

In some cases, device failure causes endless loops, PC acts dead. Requires the use of a POST card: Snap into expansion slot on computer, has LED readout.

The Boot Process

Power button turned on ? Power supply provides proper voltage to Power Good Wire ? CPU read power good wire and sends built-in memory address via address bus (1^st line of POST program ? Post passes control to last BIOS function (bootstrap loader, finds the operating system) ? first checks floppy drive, if floppy found, assumes operating system there. If no floppy in drive, looks on hard drive. In both cases, looks for boot sector. ? Passes control to operating system

Summary: CPU, Power Good, POST, Boot Loader, Operating System.

[edit section] Chapter 6: Expansion Bus

1) Connectivity

Expansion Bus: connects to rest of PC through the chipset. Function just as if it were soldered on the motherboard, difference is speed
(runs at own standard speed) ? expansion bus crystal

PC bus/XT bus: IBM's standard expansion bus, 7MHz. Allowed all to copy the PC bus, created industry standard.

ISA (Industry Standard Architecture): 8 or 16-bit, ran at 7 MHz.

2) Communication

Need to accept commands from the CPU, as well as get its attention. Expansion cards use these system resources:

I/O addresses
IRQs
DMA channels
Memory Addresses

I/O Addressing: Process of using address bus to talk to devices (address is unique combinations of 16 0's and 1's for one specific command to a given device)

To see device's I/O addresses, use device manager, resources tab on given device.

? These values are stored as Hexadecimal values

? No two devices can share the same I/O address (some hard-wired, others chosen by user moving jumper on the card)

? Other way of labeling is to drop the lead zero and add "h" ? "1F0h" = 01F0

I/O Address Map

-Includes only the most common devices (no sound /network cards)

? use unreserved addresses

(page 214) for I/O Map

Interruption

INT (interrupt) wire: tells CPU to stop doing whatever it is doing and talk to device.

COM ports ? serial devices

LPT ports ? parallel devices

Port	I/O Address	IRQ
COM1	03F8	4
COM2	02F8	3
COM3	03E8	4
COM4	02E8	3
LPT1	0378	7
LPT2	0278	5

? Com1/3 and 2/4 can't be assigned simultaneously (conflict) unless different IRQ

16-bit IRQ Map (2 8259 chips)

IRQ	Default Function
0	System Timer
1	Keyboard
2/9	Open for use
3	COM2/COM4
4	COM1/COM3
5	LPT2
6	Floppy Drive
7	LPT1
8	Real-time clock
10	Open for use
11	Open for use
12	Open for use
13	Math coprocessor
14	Primary hard drive
15	Secondary hard drive

Direct Memory Access (DMA): The process of accessing RAM without aid of CPU.

? uses 8237 chip to control all DMA functions -(avoid congestion/gives CPU priority)

- chip uses external data bus while CPU is doing internal functions

- links to the CPU through the HRQ wire (has four DRQ wires/channels)

DRQ2 = Floppy drive controller

DMA Limitations: speed (8MHz), byte-wide data

Bus Mastering: overcomes limitations of DMA by watching for devices, get out of way on the data bus on their own. (aka Ultra DMA)

PCI (Peripheral Component Interconnect): released to public domain, turned into standard for every motherboard. (32 bits, 33 MHz)

? assigns I/O address and IRQ automatically ? labeled INTA, INTB, etc.

AGP (Accelerated Graphics Port): PCI slot, but with personal connection to Northbridge. (only for graphics)

Installing Expansion Cards

1 - Knowledge

Learn about the device you wish to install (OS, drivers, etc)

2 - Physical Installation

Only touch edges, never components of connector. Avoid ESD, unplug computer.

3 - Assigning Resources to the Card

Plug and Play (PnP) assigns automatically. (All PCI/AGP = PnP). Last ISA devices were also PnP.

? Never use manual setting in CMOS unless system uses legacy devices.

? Reset Configuration Data Option to force PnP Bios to reset all devices.

4 - Device Drivers

Get the correct/most up-to-date drivers, sometimes need to remove old drivers (video cards), rollback drivers (Windows XP)

5 - Verify

Open Device Manager, make sure device is detected, then test it.

Codes:

"!" = device missing, Windows doesn't recognize, bad driver

? double-check connections, update driver

"X" = disabled device, system resource conflict, damaged device

? See if any resource conflict exists, "Change Setting Button"

"I" = PnP device configured manually, doesn't indicate an actual error

"?" = Windows doesn't have correct driver, installed compatible driver (Me)

[edit section] Chapter 7: Motherboards

Modern motherboards come in multiple layers, enables multiple wires to send data without their signals interfering with each other.

Form Factor: the particular way components are positioned on a motherboard

? two standard form factors, AT and ATX

AT Motherboards

Old style, developed by IBM in early 1980s, predominant through mid '90s. (Full AT)

?large keyboard plug, split P8/P9 style of power socket

Once smaller PCs needed, new version of AT motherboard developed (Baby AT)

Major problem of AT motherboards is the lack of external slots, later used simple connector on back of motherboard called dongle.

? LPX and NLX form factors provided a center riser slot to enable riser card (expansion cards fit into these) Problem: limited system resources - used ISA

ATX Motherboards

Developed in 1995, by 1998 it took over AT, lack of an AT keyboard port, rear panel with all necessary ports mini-DIN(PS/2) keyboard and mouse ports.

- Position of power supply provides better air flow, CPU/RAM easier to access

- Use a feature called soft power, use software to turn the PC on/off

All motherboards need proper drivers for the chipsets, found on CD-ROM with chipset drivers.

Six companies produce the vast majority of PC chipsets:

Intel, VIA, AMD, SiS, Ali, and NVIDIA

Installing a Motherboard

1. Determine the motherboards you need (what CPU is used, RAM needed, etc)

2. Determine what form factor you have, choose correct case. (slimline, desktop, mini-tower, mid-tower, or tower)

3. Ensure you have the motherboard book.

4. Check that power supply is provided, in case of "real good bargains"

5. Connect the LEDs and buttons

Troubleshooting Motherboards

PC won't boot ? Burn-in failure, replace motherboard

Component Failure ? update BIOS, replace component (due to ESD, etc)

Check, replace, verify good component ? document

Form Factor Sizes (smallest to largest): microATX, Baby AT, ATX, AT

[edit section] Chapter 8: Power Supplies

Typical power supply connects to the PC with four standard computer screws.

An electrical outlet must have a ground wire to be suitable for PC use!!

Electricity comes in DC (Direct Current): flow in one direction and AC (Alternating Current): flow of electrons alternates back and forth

Power supply: takes high power AC, converts into low power DC

? cord connects to power supply through a standard IEC-320 connector

? U.S. uses ~115 setting, other parts of world use ~230 (found on back of PC)

Use a multimeter (Volt-Ohm Meter) measures electrical current (AC, DC, continuity, resistance)

Continuity: Detect breaks in wires and components

Resistance: see if a fuse is blown, test for breaks as well

Using a Multimeter to Test AC Outlets

1. Place black lead in common (-) hole.

2. Place red lead in V-Ohm-A hole (+) hole.

3. Move selector to AV C selection (usually red), first scale higher than 120V.

4. Test socket (hot/neutral = ~115V, hot/ground = ~115, ground/neutral = 0V)

Two devices handle sags and spikes in the supply of AC:

UPS (Uninterruptible power supply): essentially a big battery that can provide AC power to computer, regardless of condition of AC outlet.

Two variations ? Online and Standby

Online: converts AC power from outlet and charges the battery, filters AC, giving smooth AC current

Standby: removes the battery from the AC circuit until voltage drops below approx. 80-90V

Surge Suppressors: protect from voltage spikes that could destroy components

? make sure surge protector has UL 1449 for 330 V rating. (at least 800 Joules)

? If using phone line (modem or DSL), get surge suppressor with phone line protection.

(UL 497A rating)

Supplying DC Power: Uses 12V to power motors (hard drives/CD-ROMs), 5 and 3.3 to power onboard electronics)

Motherboards use one or two connectors for power, P1 socket connector

? Many motherboards require another 4-wire connector, P4 connector (supplies more 12V power into the board)

Testing DC: Red lead to hot wires, black lead always goes to ground.

Power to Peripherals

1. Molex Connectors: most common, devices that need 5 or 12V, has notches

2. Mini Connectors: 5/12 V to floppy drives, possible to install incorrectly w/ little resistance.

3. Sub-Mini: single two-wire connector for powering sensors/LEDs

Splitters/Adapters: if not enough connectors to power everything, use these to substitute

If PC/devices don't receive enough wattage, most likely won't power up (needs most at startup). Recommended wattage = 400 watts.

Calculate Wattage Needed (Amperage * Voltage + Amperage * Voltage)

? Don't cut the specifications too tightly (power supplies lose after time)

AT Form Factor Power Supplies: Two power connectors, P8 and P9 must be plugged in with black wires (ground wires) next to each other (in the center) (only 12/5 Volt)

AT power switches come in two forms: Plunger and Rocker (connect to wires leading from power supply)

-AT has poor power management, Wake BIOS/LAN features almost nonexistent

Power supply fan: some come with 3-pin, 3-wire connector for built-in sensor

Ensure all empty expansion bays are covered (cause PC to overheat otherwise)

In case of fire, need a CLASS C Fire Extinguisher

[edit section] Chapter 9: Floppy Drives

3 ½ inch, 1.44MB capacity

Formatting a floppy tells it how the data will be stored (PC/Mac use different formats)

Formatting a floppy disk creates four distinct areas:

1. Boot Record: program that runs when you boot the computer

2. File Allocation Table: spreadsheet containing addresses of all files stored

3. Root Directory: base of the directory tree (parent to all other directories)

4. Data area: contains all other information, the actual files

Three disk types, only one not obsolete is double-sided, high-density disks

All windows systems reserve the drives A and B for floppy drives

? connect via a 34-pin ribbon cable

? 7-wire twist used to show support for two drives (most systems dropped this)

Inserting Ribbon Cables: orient cable so that colored stripe is aligned w/ pin 1.

? if inserted incorrectly, the drive will simply not work.

End Connector = Drive A Middle Connector = Drive B

? 3 ½ use Mini power connector 5 ¼ use Molex power connector

After the floppy drive is installed, configure in CMOS under

"Standard CMOS Settings/Storage"

Repairing Floppy Drives

1. Check for bad floppy disk

? try inserting another disk

2. Check for data errors on disk

? either reformat (lose data) by right-clicking floppy drive, choose format, or use recovery software

3. Check CMOS

? rarely cause problems, worth checking formatting though

4. Blame floppy controller

? check for loose cable, CMOS? disable onboard FDD controller (otherwise, do through device manager). Troubleshoot from PCI FDD controller card

5. Check the cable

? 34^th wire called the drive change signal, lets PC know when disk inserted/removed. If LED stays on, there is a reversed cable. If LED never comes on, both cables reversed.

6. Replace floppy drive

[edit section] Chapter 10: Hard Drive Technologies

IBM Advanced Technology (AT) Computer in 1984 = first hard drive

Consist of individual disk (platters) with read/write heads (two heads to a platter)

-spin at speeds of 3500 to 10,000 rpm

Data stored in tiny magnetic fields, data fluxes, difference between N/S was 0 or 1

Geometry of Hard Drive: Cylinders, Heads, Sectors/Track
Methods of Encoding

Frequency Modulation (FM): took up 50 percent disk space, used timing bits
Modified FM (MFM): timing bits placed after 2 consecutive zeros
Run length limited (RLL): unique patterns of 0's and 1's to represent longer patterns
Partial Response Maximum Likelihood (PRML): advanced RLL

Hard Drive Interfaces

IDE (Parallel ATA and Serial ATA)
SCSI (Small computer system interface)

In old days, hard drive controller a separate card that installed in expansion slot, had to erase all the geometry (low-level formatting)

Parallel ATA (PATA): aka IDE, requires ribbon cable and built-in controller

EIDE: series of improvements over IDE, higher capactities, support for non-hard-drive storage devices, two or more ATA devices (max of 4)

IDE drives connect ? 40-pin plug and a controller

Almost all PCs provide 2 EIDE controllers, each one supporting two ATA drives (manifest as two 40-pin male ports) IDE1 = primary IDE2 = secondary

Old 'model uses 40-pin, 40-wire '''New 'model uses 40-pin, 80-wire

How to Identify Each Drive on the Cable

PATA standard uses "master" and "slave" drives.

? if only one hard drive, set jumper to master

? if two drives, set one jumper to master, one to slave

Many current PATA drives use cable select instead of master/slave.(Master on end, slave in middle) ? also needs special cable, ribbon-cable with pinhole though one wire

*Make sure Pin 1 on controller is on same wire as Pin 1 on Hard Drive* Plug Molex connector into hard drive to power.

An extension to the ATA specification ?

(ATAPI - Advanced Technology Attachment Packet Interface): allows non-hard drive devices to connect to the PC via the ATA controllers. (Need option ROM/device driver)

Serial ATA: addresses ATA cable airflow, length (18 inches), and can't hot-swap

- Sends data serially rather than in parallel, uses 7-wires, allows thinner cabling

- cable length of 1 meter (39.4 inches)

- hot-swappable

- sends data up to 30x faster

- backward compatible with PATA standards using SATA bridge

Can add SATA capability through PCI card

? no jumper settings, master/slave, etc. (just plug power and controller cable)

Configuring CMOS

After installing a PATA hard drive ? enter its geometry

Hard Drive Types: IBM established types, rather than individual values, to be set

? as new hard drives released, became impractical, USER type used

On today's systems, just set the hard drive type to "Auto"

- Original AT BIOS only allowed 504 MB hard drive**

LBA/ECHS: hard drive lying to the computer about its geometry (sector translation)

Sector translation: reports geometry to the BIOS that is totally different from true geometry of the drive (never changes capacity)

LBA/ECHS = maximum 8.4GB hard drive

INT13 Extensions (Interrupt 13): ignores the CHS values, feeds LBA stream of "addressable sectors", handle up to 137 GB

many systems require you to set the drive to Auto ONLY

ATA/ATAPI-6: industry proposal, Big Drives = 144,000,000 GB (petabytes)

PIO (Programmable Input/Output): standardized protocol for ATA drives

Setting PIOModes (data transfer rate from hard drive-memory)

PIO Mode	Transfer Rate (MBps)
0	3.3
1	5.2
2	8.3
3	11.1
4	16.6

What is the fastest mode the hard drive/controller/BIOS (or device driver) supports?

? Fastest mode is determined by the "weakest link"

DMA (Direct Memory Access) Modes: newer hard drives use this, bypass the CPU (sends data directly into memory) 16 or 32 bit transfers

Ultra DMA 4 = ATA/66 (66 Mbps) Ultra DMA 5 = ATA/100 (100 Mbps)

ATA/66, 100, and 133 controllers built into motherboards, require 80-wire cable, usually some bright color to distinguish them.

ATAPI Devices: CMOS seems to autodetect, but doesn't dome w/ true BIOS support (need device driver at bootup)

RAID (Random Array of Independent Disks): requires SATA Raid Controller Card

Disk Mirroring: Reads and writes data at the same time (simultaneously on both drives)

Drive Duplexing: using two separate controllers for two separate hard drives (faster than single controller)

Disk Striping w/o Parity: spread the data on at least 2 drives, very fast, AVOID

? with parity: protects data, adds parity data (at least 3 drives)

RAID 0 - Disk Striping: no redundancy to data, one drive fails, all is lost

RAID 1 - Disk Mirroring/Duplexing: use any even # of drives, ultimate in safety

RAID 5 - Disk Striping w/ Distributed Parity: most common, at least 3 drives

Implementing RAID

Use either SCSI, or ATA RAID Controller cards (support 15 drives)

Hardware or Software?

? Software is price over performance (Disk Management) can do

0,1,5 (Win NT), no 5 in 200/XP Professional

? Hardware needs intelligent controller, most use CMOS settings from Flash ROM to configure

Steps in Physical Installation

Power down/unplug system
Determine speed/size motherboard can handle
Decide which controller you will install (best is primary controller as a slave)
Set jumpers (single master is different than master with slave)
Reinstall the cable
Plug in power cables on both drives (standalone Molex)
Provide any needed BIOS for the controller

[edit section] Chapter 11: Implementing Hard Drives

After installation, need to partition a drive and format the drive.

? May have only 1 physical drive, but can use 24 logical drives (C: to Z:))

? partitioning allows more than one operating system

2 partition types: Basic Disks (all versions of Windows) and Dynamic Disks (2000/XP)

Partitioning Basic Disks (FDISK)

- Creates the Master Boot Record (MBR) and the partition table. (both in boot sector)

MBR: looks for a partition in the partition table with a valid OS

A hard drive may have up to 4 partitions*

Primary Partition: stores the OS, hard drive must have this in order to boot (C:)

FDISK: 3.x, 95,98, ME all use this.

To partition, needs: Create partition, Set Active Partition, Set Primary Partition, Set Extended Partition

1) Set Primary Partition (50%)

2) Set Extended Partition (50%)

3) Create logical drives from the extended partition (25% each)

Disk Administrator

Windows NT 4.0 uses this, uses graphical interface

Disk Management

Windows 2000/XP, works just like Disk Administrator

Dynamic Disks divided into volumes, no longer extended partitions (XP Home doesn't support)

Mount Points: drive that functions like a folder mounted into another drive.

Drive converted from basic ? dynamic can't be reverted without all data being lost.

Formatting Hard Drives

Creates a file system and makes the root directory in that file system.

Different types of File Systems: FAT16, FAT32, NTFS4, NTFS5

FAT16: File Allocation Table, keeps record of file and the memory addresses it is stored in. Each sector given a 4-piece Hex number (16 bits), thus, FAT16.

? 32 MB partition limitation

- clustering used to overcome limitation (now up to 2 GB)

FAT32: supports partitions of up to 2 terabytes, uses 32 bits to describe each cluster

NTFS4: Windows NT 4.0, uses Master File Table (MFT), keeps backup of this table, views individual files/folders as objects and provides security for them, file compression

NTFS5: 2000/XP offer this, allows better encryption, setting limits on hard drive space used by users, allows mounting a volume as a folder

To encrypt files/folders, right-click, click Advanced button, chooses encrypt option

Disk Quotas prevent users from using up "too much" space on a shared drive.

Formatting a Partition

? If you click on drive and error occurs, you forgot to format the partition

To format, command line: format x (x is the drive letter), or right click, select format

? Disk Administrator (NT) and Disk Management (2000/XP) can also format

On New/Rebuilt System: boot to the OS CD-ROM, or boot to floppy in Window 9x and at command prompt, type format C:/s

(to see status before OS installed, type FDISK/status at command prompt)

Maintenance of Hard Drives

ScanDisk: checks for bad clusters, fix invalid filenames, looks for clusters with no filenames associated with them and deletes them

Windows 9x/ME: Start | Programs | Accessories | Systems Tools

Windows 2000/XP: My Computer, alt-click drive, select properties, tools tab

Defragmenter: found in same location as ScanDisk for all systems

Disk Cleanup: files in recycle bin, temporary internet files (Start | Control Panel | Internet Options applet | Settings | View Files), downloaded program files, temporary files

Troubleshooting

Check connectivity, CMOS, portioning, and formatting.

1. Install Cable in backwards = computer won't boot

2. Power cable installed backwards = destroy hard drive

3. CMOS: Always run autodetect and always choose LBA

4. Partions: failing to partition at all, and portioning wrong size/type

5. Failing to format makes drive unable to hold data

6. "Trying to recover lost allocation unit" indicates dying drive

7. Bad Boot Sector: run antivirus program, try FDISK /MBR at bootup

Dynamic Drive Overlays: Allows older systems to use newer drives, avoid if at all possible

Data Corruption: core boot files corrupted give errors like "Invalid Boot.ini", "Error loading OS", "Cannot find COMMAND.COM" ? run ScanDisk.

? if ScanDisk doesn't fix it, Extract/Expand from Cabinet Files

Cabinet Files (.CAB): stored files in a compressed format.

EXTRACT = 95/98 EXPAND = 2000

EXPAND C:\I386\*.CAB -F:[cabname] C:\

[edit section] Chapter 12: Understanding Windows

Four Main Responsibilities

1. Communicate with hardware

2. Provide a user interface

3. Provide a structure for access to applications

4. Enable users to manipulate programs and data

- OS only work with certain types of processors
- Application programs can't run on PC without OS

COMMAND.COM: DOS user interface (input ) provided from this file

IO.SYS: act as intermediary between most common hardware and the video

CONFIG.SYS: Load device drivers, allow legacy devices

? HIMEM.SYS (load graphical portion of OS) and EMM386 appear

AUTOEXEC.BAT: file containing all DOS commands that you wanted to run at startup, allow legacy devices

Revealing File Extensions:

95/NT ? View | Options | View Tab | Uncheck Hide Box

98 ? View | File Options | etc…..

Me/2000/XP ? Tools | Folder Options | View Tab

Windows NT 4.0 doesn't support PnP ? No device manager

Start | Accessories | System Tools ? all system tools found here

Microsoft Management Console (MMC): shell program in 2000/XP that holds individual utilities called snap-ins (Run: MMC)

Administrative Tools: combined snap-ins under Administrative Tools Applet

1. Computer Management: System Tools, Storage, System Information

2. Event Viewer

3. Performance: System Monitor and Performance Logs/Alerts

4. Services: Runs support to system, but is invisible

The System Folder: Name given to folder where Windows is installed (C:\WINDOWS usually) ? %SYSTEMROOT% (%Windir% for Windows 9x systems)

The Registry: stores everything about your PC (hardware, preferences, file types, etc)

Windows 9x/ME: composed of SYSTEM.DAT and USER.DAT in root folder

		Settings \| Control Panel)
		also use command prompt: regedit

Registry Components

1. HKEY_CLASSES_ROOT: defines the standard class objects (named group of functions) used by Windows. (file associations)

2. HKEY_CURRENT_USER/USERS: user preferences stored here

3. HKEY_LOCAL_MACHINE: contains all the data for a system's non-user-specific configurations (every device)

4. HKEY_CURRENT_CONFIG: if local machine has more than one option (two monitors), this defines which one is currently being used

5. HKEY_DYN_DATA: Registry data that is stored in RAM to speed up system configuration (not in Windows 2000)

Windows NT/2000/XP: registry files called hives located in systemroot/system32/config

? To access, run regedt32. More powerful, but use regedit for better searches

The Swap File: Extension of system RAM, used when RAM is low. Processes swapped to swap file, RAM is then freed up. (also known as virtual memory)

-Looks at what program is the least used, that is the "swapped" file

-If program opened up again, program is pulled out of swap into RAM

Windows 9x/ME: swap file is WIN386.SWP (often in windows folder)

Windows NT/2000/XP: swap file is PAGEFILE.SYS (often in root directory)

With multiple hard drives, performance boost by having swap file on secondary drive

To change location of swap file

Control Panel | System Applet | Advanced Tab | Perf. Settings | Advanced Tab

Windows 9x/Me has 16-bit and 32-bit (protected mode) components

? really two products: DOS protected mode (DPMI) and protected mode GUI

DPMI consists of: IO.SYS, MSDOS.SYS (startup options files), COMMAND.COM needed for a C prompt/autoexec.bat

Windows Me: can't boot directly to command line interface

-Later versions of Windows 95 and up support FAT32

Filename Conventions: DOS/Win 3.x use 8.3 convention (8 chars, period, 3 chars)

(255 chars for Windows 9x/Me)

Boot Menu: IO.SYS checks if F8 is pressed, if it is, open Windows boot menu.

Options:

Normal
Logged (creates log file of boot process)
Safe Mode (F5 also) (only OS, mouse, keyboard, VGA video drivers are loaded. AUTOEXEC.Bat/CONFIG.SYS aren't loaded)
Safe Mode with network support
Command prompt only (starts all startup files, not the gui)
Safe mode command prompt only (skips all startup files)
Previous version of MS-DOS (don't use with FAT32/previous DOS version)

MSDOS.SYS: now a text file in C:\ drive, replaces AUTOEXEC.BAT and CONFIG.SYS functions that are still needed by the OS for the GUI to kick in

? Provides boot options

? Doesn't load device drivers/TSRs

After OS-files and config files/utilities loaded:

? WIN.COM runs .INI files

Format of INI files

[Group Header]

item = settings

[Group Header2]

item2 = settings

SYSEDIT ? also edited with EDIT.EXE and Notepad

1. Autoexec.bat

2. Config.sys

3. System.ini

-all resources were initialized here, not needed on Windows 2000/XP

4. Win.ini

-defined all the personalization of Windows (fonts, screensavers, display colors)

- [386Enh] stores drivers for 386 protected mode, add ";" in front of problem line

-"LOAD =" and "RUN=" act like hidden startup group

Startup Disk: special bootable floppy disk that contains a number of utilities that helps fix a system that won't boot

Windows 95: doesn't support a CD-Rom drive

System Information Tool: provides snapshot of your system, provides a launch point

Windows Update: Windows 9x/Me ? Start | Windows Update

Windows XP/2000 ? Start | Programs | Windows Update

Internet Connection Sharing: allows multiple PCs to share same dialup connection

Network Neighborhood (95/98) = My Network Places (Me/2000/XP)

- - Windows ME introduced System Restore***

Windows NT

OS separated into three parts: the drivers, the NT Executive, and the subsystems.

-supports symmetric multiprocessing (supports up to 32 processors)

-uses NT file system (NTFS)

NTFS:

long filenames: up to 255 chars

redundancy: backup of critical parts of MFT

backward compatibility : can copy DOS or windows programs to an NTFS platform

recoverability: uses transaction logging to restore file to original format

security: accounts, groups, permissions

Need an account to log in, group is a collection of accounts that share the same access capabilities

Administrators: complete access

Power Users: can't install new devices

Users: can't edit the registry/access critical system files, can create groups

Backup Operators: can run backup programs that access any file or folder for backup uses only

Replicator: Members can replicate files and folders in a domain

Everyone: applies to any user that can log onto the system

Guests: doesn't have an account, used in network situations

NTFS Permissions

Ownership: when you create folder/file, you are the owner, prevent even admins.

Take Ownership Permission: enables anyone to seize control of a file

Change Permissions: give/take away permissions for other accounts

Folder Permissions: select folder | properties | security tab

File Permissions: full control, modify (can't delete file), read/execute, list folder contents, read, write

Note: Windows XP Home only offers one option: Make this folder private

Boot Files: Windows 9x/Me boot files on C: partition, GUI on any other drive

Windows 2000/Xp boot files on boot partition, boot/GUI closely linked

The Boot Process

CPU wakes up ? Runs BIOS ? BIOS seeks valid OS in boot sector of primary partition ? Master File Table (MFT) points to location of NT boot files

System Partition = initial boot drive

Boot Partition = area that stores the OS's GUI files

Windows NT Family (NT, 2000, XP) boot files include:

1. NTLDR -begins the process, launches OS, reads the BOOT.INI config file

2. BOOT.INI - text file that lists available Oss, and where to find them

To edit in Win 2000, System Applet | Advanced Tab | Startup and Recovery

3. NTDETECT.COM - detects the installed hardware on the system

4. NTBOOTDD.SYS - if boot partition on a SCSI drive that lacks a ROM chip

Files and Settings Transfer Wizard

Run Wizard ? prepares old drive? connect old hard drive to new drive ? run wizard

Chapter 13: Working with the Command Line Interface ==

Windows NT 4.0/2000/XP ? Start | Run | Type CMD

Windows 9x/ME ? Start | Run | COMMAND

-OR- Start | Program | Accessories -OR- Windows Key + "R" at the same time

Filenames/Formats: filename.extension (8.3 format for true DOS) ? N/A for Win 9x+

First 32 ASCII characters used for special commands

<u>The Command Prompt

Always focused on a specific folder, commands issued are performed on the files in the folder which the prompt is focused.

Structure: Syntax and Switches

[command] [target] [switches] ? type "/?" for help on commands

The Dir Command

-Shows the contents of the directory where the prompt is focused

-Dir /w lists only the filenames

The CD Command

-The cd/chdir command changes the current working directory

-CD\ returns you to the root directory (C drive usually)

-CD.. takes you up one level

-CD [space] directory also works

-NOT used to move between DRIVES (C: ? A:)

? To switch drives, type drive letter and colon

Making Directories (MD/MKDIR)

-Make sure that the prompt points to the directory in which you want to make the new subdirectory

Removing Directories (RD/RMDIR)

-Will not work if directory has files or subdirectories

? DELTREE/ Del /s command will delete all files and subdirectories

To run a program, move to directory with program and type programs name and enter

File Attributes -run ATTRIB [filename] to view/change attributes

1. Hidden: won't be displayed when DIR command executed

2. Read-Only: can't be modified/deleted

3. System: used as easy identifier for system files

4. Archive: used by backup software to identify files that have been changed since their last backup

To add attribute: ATTRIB +R [filename]

To remove attribute: ATTRIB -R [filename]

Multiple changes: ATTRIB +H -R +S [filename]

Wildcards: Asterisk (*) or Question Mark (?)

Renaming Files (REN/RENAME)

Ren [original filename] [new filename]

?To rename to more complicated, use quotation marks

Deleting Files (DEL/ERASE)

DEL [filename]

-DEL *.* will elicit a response

-will not delete directories

Copying/Moving Files (COPY/MOVE)

-only difference is that copy retains original, move MOVES the file to new location

Point to directory with file, type copy or move, type path of new dir, press enter

? to rename file while being moved/copied: copy resume.doc A: \newName.doc

XCOPY: ability to work with multiple directories

? XCOPY C:\Data D:\Date /S copies all files/subdirectories from C to D

			? /S is a switch that tells it to copy all subdirectories except empty ones
			? /E tells it to copy even the empty directories

Batch Files: text files that store a series of commands, one command per line (.BAT extensions)

In C:\, type EDIT. To save: alt + f + s

TYPE [filename] outputs the content of the file

SETVER: ran programs in certain DOS versions

[edit section] Chapter 14: Installing and Upgrading Windows

Before you insert the install disk:

1. Identify hardware requirements

2. Verify hardware/software compatibility

3. Decide between clean installation/upgrade

4. How to backup/restore data if necessary

5. Select an installation method

6. Determine how to partition the hard disk and what file system to use

7. Determine computer's network role

8. Decide on computer's language and locale settings

9. Plan for post-installation tasks

Identify Hardware Requirements: RAM, CPU, hard drive space, video adapter

Verify Hardware and Software Compatibility: use HCL (Hardware compatibility list)

Decide between clean installation/upgrade: clean = empty hard drive

? can't upgrade from Windows 9x/Me to NT

Determine Backup/Restore Data: Save data to network location, or save to CD-R

Select an Installation Method: Bootable CD/Floppy (Setup.exe or Winnt32.exe), XP boots only from CD Remote Installation Services: initiate scripted installation/image

Determine Partition/File System: use best file system available, lowest-common denominator for multi-boot Oss

Determine Network Role: Stand-alone, workgroup (XP Home), or domain

Decide on Computer's Language/Locale Settings: date/time, currency symbols

Post-Installation Tasks: install latest service pack/update, updated drivers, install applications, restore backed up data

Performing the Installation/Upgrade

1) Text Mode: inspecting the hardware, display the End User License Agreement, partition hard disk, then reboots

2) Graphical Portion: Enter the product key, select configuration options/optional components

Installing Windows 9x/Me

Component	Minimum	Recommended
CPU	Pentium	Pentium 2
Memory	32MB	64-128MB
Hard Disk	455-635MB	4GB
Display	640x480 @16 colors	SVGA or higher
Other	Mouse, CD-ROM, soundcard	Mouse, CD-ROM, soundcard

Almost always use FAT32 unless need to support old DOS program, old version of Win95, or multi-booting older OS (Win98 uses CVT.exe to convert FAT16 to FAT32)

When upgrading from Win 95 to 98, must install files in same folder that held OS files for Win 95 (default is C:\Windows).

Installing Windows NT 4.0

Doesn't support PnP, test by: Run \Support\HQTOOL\MAKEDISK.BAT from installation CD, restart computer and boot from disk

Component	Minimum	Recommended
CPU	Intel 80486 25 MHz	Pentium 150 MHz
Memory	12 MB	64 MB
Hard Disk	128 MB	2 GB with 1 GB Free
Network	None	Modern PCI
Display	VGA resolution	SVGA resolution (16-bit)
Floppy disk drive		High density

Go with NTFS file system

Needs to be patched after installation since it is an old system (Service Pack 6a)

Installing Windows 2000 Professional

Component	Minimum	Recommended
CPU	133 MHz	Pentium 2 350 MHz
Memory	64 MB	128 MB
Hard disk	2 GB w/ 650 MB free	6.4 GB w/ 2 GB free
Network	None	Modern PCI
Display	VGA	SVGA (16-bit)
CD-ROM		12x (non-network)
Floppy Drive		High Density

To upgrade from NT 3.1 or 3.5, need to upgrade first to 3.51 or 4.0

Windows 2000 doesn't support applications that use Virtual Device Drivers

Command Line: WINNT32.EXE /CHECKUPGRADEONLY = compatibility report

Installing Windows XP Professional

Can't upgrade from Windows 95 or NT (lower than 4.0)

Component	Minimum	Recommended
CPU	233 MHz or higher	300 MHz or higher
Memory	64 MB	256 MB
Hard disk	1.5 GB available	4 GB available
Display	Direct X 8, 800 x 600 resolution	Direct X 8, 800 x 600 resolution

Two tools for determining hardware compatibility

1. Windows Catalog: searchable list of hardware/software that is known to work with XP

2. Upgrade Advisor: runs on installation CD. "Check System Compatibility"

**You have 30 days upon installation to activate Windows**

Troubleshooting Installation Problems

"No Boot Device Present…" ? startup disk is bad, CMOS not set to look at floppy first

"Windows has Detected that Drive C: Doesn't Contain a Valid FAT" ? forgot to partition, trying to install on a partition that Windows doesn't understand

"Windows Setup Requires XXXX Amount of Available Drive Space" ? format drive, delete things on drive to free up space

"MSCDEX Error "No CD-ROM Detected" ? check CONFIG.SYS and AUTOEXEC.BAT (CD-ROM driver is messed up)

"Not Read Error on CD-ROM" ? give CD-ROM a moment to catch up (r for retry)

Blue Screen of Death ? often due to hardware compatibility issues

Can't Read .CAB Files: Try copying all files onto hard drive and running from there

Lockup During Install: unplug computer if it freezes, Windows resumes installation with only mandatory hardware (troubleshoot problem devices later)

Log Files: track the progress of certain processes.

1. SETUPLOG.TXT: tracks the complete installation process (registry updates)

2. DETLOG.TXT: created during hardware detection process

3. BOOTLOG.TXT: tracks the boot process as each device driver/program loads

[edit section] Chapter 15: Windows 9x and Windows Me

Tip: The order in which you install patches in Windows 95 can be crucial

OEM service release 1 (OSR 1): Windows 95 with Service Pack 1 already installed

Customer Service Pack: The major update that was for Windows 98

? Windows 98 SE included this update

Windows Update Utility: Click start button on Win 98/Me

? For Win 95, download QFECHECK from Microsoft

Switch drive of swap file and changing its size to 2-3 times RAM is more efficient

Disk Cache: Change through System Properties | Performance Tab | File System Button

Typical Role: Setting to server gives moderate performance boost

Read-Ahead: Allows cache to store more clusters of info at a time

Resource Tracking Tools

System Resources: On performance tab of system properties (% of resources free)

System Monitor: snapshot of system processes Program | Acc. | Sys Tools | Sys Mon

System Resource Meter: view heaps on computer (what programs are slowing down the system) (Same location as System Monitor)

Task Manager: ctrl + alt + delete, shows all running (and hidden) programs

Auto-Starting Programs: Check systray, WIN.INI (MSCONFIG), AUTOEXEC.BAT

? Windows 95: Windows | Start Menu | Programs, then run SYSEDIT

Startup Disk: Start | Settings | Control Panel | Add/Remove Programs | Startup Disk Tab

To Backup Registry: open C:\Windows\System, then turn off all file attributes for SYSTEM.DAT and USER.DAT, copy into backup folder

-OR-

Use REGEDIT, export Registry File Option

Device Drivers: extension is .INF

Possible Problems with PnP Devices

Outdated Support Drivers, Outdated BIOS, Resource Conflict, Corrupted Registry, Bad Device

IRQ Steering: Originally, IRQ's were assigned for every PCI/AGP device, even though they didn't actually need them. This wasted tons of IRQs. With IRQ steering, PCI devices share one or more IRQs. Needs IRQ 9 or IRQ 11 available for steering

Windows Memory: "Memory Range", devices that need a range of memory addresses

Installing Legacy Devices

1. Run system information tools to determine all devices on the system.

2. Configure device to use available system resources.

3. Install device, start the system.

4. Install device's application, if problem, assume DMA/IRQ conflict.

Four Types of Backups

1. Copy: copies selected files and folders to the backup device without turning the archive bit

2. Full: backs up every file and folder and turns off the archive bit

3. Incremental: Backs up only files and folders with the archive bit turned on, and turns off the archive bit

4. Differential: Backs up only files and folders with the archive bit turned on, but does not turn off the archive bit

System Restore in Windows Me: creates restore points each day.

? Create a restore point: Start | Programs | Accessories | System Restore

Recovery CDs: Restore system to the point it was at during the time it was delivered, lose all data.

Virus Types

1. Boot Sector: change the code in the Master Boot Record, resides in memory (Remove using the FDISK /MBR command)

2. Executable: reside in.exe files, loads into memory after being run

3. Macro: auto-start when the particular application is run

4. Trojan: programs that do something other than what the person thinks it does

5. Worm: doesn't infect other files, replicates through network/internet

6. Bimodal/Bipartite: uses both boot sector and executable functions

Windows Boot Problems

1. No OS Found: Corrupted/missing IO.SYS or MSDOS.SYS ? run SYS C:

2. Bad or Missing COMMAND.COM: use startup disk to copy the file into C:\

3. Error in CONFIG.SYS: add semicolon in front of conspicuous lines

4. Device Referenced in SYSTEM.INI Not Found: same as above

5. HIMEM.SYS Not Loaded/Missing/Corrupt: add this to CONFIG.SYS using EDIT ? DEVICE=C:\HIMEM.SYS, then copy HIMEME from disk to C drive

6. Won't boot to GUI (locks up at Windows screen)

a. First blame swap file: boot into safe mode, disable virtual memory

b. If not, restore the previous registry copy

c. Start | Run | ASD ? won't load bad drivers

d. Run system file checker in case of corrupted core Windows Files

i. SFC /SCANBOOT /QUIET

General Protection Fault (GPF): occurs when one program "stomps" on another program's memory

Windows Protection Errors: when virtual device driver (VxD) fails to load/unload

? Run SYSEDIT ? check CONFIG.SYS Device = settings

Sound File: if the windows shutdown file corrupts, the system will not shut down. Use sound applet to turn off shutdown sound.

[edit section] Chapter 16: Windows NT, 2000, and XP

MMC: not found in Windows NT

Run WINMSD to run System Information Utility

Event Viewer: Control Panel ? Performance/Maintenance ?Admin Tools ? E. View

Application, Security, System

Task Manager: ctrl + shift + escape in NT/2000/XP, ctrl alt delete otherwise

- Windows NT doesn't have Disk Defragmenter or Disk Cleanup **

Driver Signing: driver has digital signature which are issued by Microsoft stating they were tested and work.

While installing PnP, if Windows doesn't detect, use the Add New Hardware Wizard

Managing User Accounts and Groups

User and Password Applet in Win 2000

Alt-click My Computer | Manage

Users Accounts Control Panel Applet in Win XP

Task Manager: shows Handles (interlinking of programs), Threads (DLL), Processes

Performance Monitor: Performance Snap-In, or run PERFMON

	System Restore	Backup Restore Wizard	Automated System Recovery	Emergency Repair Disk	Recovery Console
Windows NT 4.0	No	Yes	No	Yes	No
2000 Professional	No	Yes	No	Yes	Yes
XP Home	Yes	No	No	No	No
XP Professional	Yes	Yes	Yes	No	Yes

Win 2000 ERD: Stored in \WINNT\REPAIR

? contains SETUP.LOG, AUTOEXEC.BAT, CONFIG.NT

Too add System Restore to Startup: d:\i386\winnt32 /cmdcons

fixboot = write new boot sector into the system partition

[edit section] Chapter 17: CD and DVD Media

CD-ROM: 74 Min (650 MB of data), uses lands and pits to record 0's and 1's

? special format called CD-DA (CD-digital audio) ? no error checking

? developed new format, ISO-9660 (High Sierra), also CD-ROM format

Speed = 150KBps 6x = 150 * 6 = 900 KBps

Single-session drive: can only undergo one burn process

Multi-session drive: can undergo multiple burn processes

Write Speed * Rewrite Speed * Read Speed

DVD: 4.7 GB, can be dual or single sided, single or dual layer, and uses smaller pits.

DVD Multi: can read all 6 versions of DVD disks

Installing CD and DVD Media Drives

Uses either ATAPI or SCSI drives:

ATAPI (ATA Packet Interface): extension of EIDE, treats CD-ROM exactly as if it were a EIDE drive. Uses 40-pin connectors, and master/slave jumpers. Doesn't require CMOS changes

SCSI (Small Computer System Interface): predates ATAPI, known as SCSI chain

Before Windows 95

Device driver added to CONFIG.SYS, MSCDEX run from AUTORUN.BAT

MSCDEX: Microsoft CD-ROM Extension, takes the device name and assigns it a drive letter

? Drive name in CONFIG.SYS must match the one in AUTOEXEC.BAT

Windows 95 and Up

Replaced MSCDEX with protected-mode CD File-System (CDFS) driver, part of the Windows Installable File System (IFS)

Change drive name in 2000/XP using Disk Management Snap-In

AUTO Run File = AUTORUN.INF

Buffer Underrun: caused when source device can't keep the burner loaded with data

? caused by small buffers and running multiple programs during burn process

Red Book = Audio Yellow Book = Data White Book = Video

Orange Book = Recordable CDs

[edit section] Chapter 18: Video

CRT (Cathode Ray Tube) Monitors: three electro guns, display screen (with phosphor coating), stream of electrons shoot towards coating

Yoke: ring of electromagnets in monitor

Refresh Rate: start at upper left to lower-right, these sweeps are called Raster Lines

		? speed at which the raster line moves across the screen is Horizontal RR
		? amount of time to cover entire screen at reset is Vertical Refresh Rate
		? pushing too high of a VRR can destroy monitor

Phosphors (red, green, or blue) on monitor, electron guns fire light, make phosphors glow. Behind this is the Shadow Mask, which filters only the proper light (prevents bleeding over)

Resolution: horizontal pixels x vertical pixels (most use a 4:3 aspect ratio)

Dot Pitch: the diagonal distance between phosphorous dots of the same color

Bandwidth: the # of times gun can be turned on/off in a second (MHz)

? max VRR = bandwidth / resolution

LCD (Liquid Crystal Display) Monitors: uses property of polarization to display colors

? all have a native resolution, which enables them to display the sharpest picture possible

For customizing: Start | Control Panel | Display Applet | Appearance Tab

Contrast Ratio - the difference between the darkest and lightest spots on monitor, good ratio is 450:1

CRT Size: described in monitor size and screen size (VIS, or viewable image size)

LCD Size: express only VIS value

Connections: CRT = 15-pin, three row, CB type connector

LCD = Digital Video Interface (DVI) standard DVI-D(digital) or A(analog)

Power Conservation: Benefit is lower power consumption, less startup time than simply shutting off monitor (25 watts, screen return in less than 10 seconds)

The Video Card

-consists of the video RAM and the video processor circuitry

2 colors = 1 bit (mono)			4 colors = 2 bits	16 colors = 4 bits
256 colors = 8 bits		64k colors = 16 bits		16.7 million colors = 24 bits

Modes

VGA: video graphics array, 16 colors at a resolution of 640 x 480 pixels

SVGA: any video card with resolution greater than VGA

XGA: extended graphics array, 1024 x 768 with 16 bit colors

To determine if you have enough memory:

Convert color bit depth into bytes, multiply this result by resolution, divide to get MB

Max bandwidth of PCI cards is roughly 132 MBps (33MHz)

(ISA = 8 MHz)

Led to creation of AGP (you will never find two AGP on the same motherboard)

(66 MHz)
Runs on own personal databus
Pipelining commands
Sidebanding (basically a second data bus for more commands)
close connection tolerance required (tight fit to motherboard)

Low-end video cards use DRAM (needs to be refreshed, causes bottleneck)
High-end cards need to be installed away from PCI slot (leave one blank to prevent overheating), or change motherboard, case, or card if too big

Installing and Configuring Video Software

Install drivers, customize with display applet in control panel

(as a basic rule, uninstall old driver, install new one)

? Nice feature is Appearance | Effects button, change from standard to clear type

Settings: Screen Resolution and Color Quality settings

Advanced | Monitor ? change refresh rate

3-D Video Cards:

video card instruction set standards manifested into

APIs, or Application Programming Interfaces

? a translator, which takes commands issued by the program, translates them into a language the device driver can understand

DirectX: takes direct control over certain pieces of hardware, bypasses the OS. Allows for speeds necessary to run most modern games

Starting with Windows 98, dual-monitors supported

Internal Adjustments: high-voltage anode has the most voltage (25,000 volts)

[edit section] Chapter 19: SCSI

Any type of peripheral can be built as a SCSI device

SCSI Chains: SCSI manifests itself through this, a series of SCSI devices working together through a host adapter.

Host Adapter: provides the interface between the SCSI chain and the PC

? aka SCSI controller

Internal Devices: connect with 68-pin ribbon cable

External Devices: connect with 50-pin high density connector

? red ribbon oriented towards pin 1

- improper installation can destroy both the device and the SCSI controller **

Daisy-chaining allowed, up to 15 devices to one host adapter (plus the host adapter)

SCSI IDs: since all on the same chain, need a way to differentiate (range from 0-15)

- can have any ID as long as it is available (order doesn't matter)

- two devices can share an ID only if on separate chain

- host adapter usually ID 7 or 15

- set ID though jumpers, dials, etc. (varies for each device)

- most use 4 jumpers, A0 - A4 (binary values 0,2,4,8)

Logical Unit Numbers: SCSI supports more than one device per ID is you use this, uses a unique identifier for up to seven sub-units per ID number (hard-drive arrays)

Terminating the SCSI chain is necessary to prevent echo/electronic chaos

? terminate only the ends of the chain

SCSI Flavors

SCSI-1 ? 8-bit, 5-MHz bus, support up to 8 SCSI devices,

SCSI-2 ? definition of 18 commands that had to be supported,

called common command set (CCS)

-could be 8-bit (narrow), 16/32 bit (wide), 5 MHz (slow), or 10 MHz (fast)

SE: Single-ended system, uses 8 wires on data cable (6 meter chain allowed)

HVD: High Voltage Differential, uses inverse wire (25 meter chains allowed)

LVD: Low-Voltage Differential, can mix-and-match with SE and HVD (12 meters in length allowed)

SE	6 Meters
HVD	25 Meters
LVD	12 Meters

SCSI-3 ? allows hot swapping (unplugging SCSI device without needing to reboot)

Termination

1. Passive Termination: network of resistors

2. Active Termination: uses voltage regulators instead

3. Forced Perfect Termination (FPT): uses diodes (lower resistance in one end than in the other, called polarity)

To communicate between separate SCSI devices directly, uses Bus Mastering

Cable and Connectors

Type A = 50 wires, used for 8-bit data transfers (SCSI 1 and 2)
Type B = 16-bit data transfers, 68 wires used in parallel with Type A cable
Type P = 68 wires, used alone unlike Type B
Type D = SCSI-3 host adapters, 80-pin, extra wires enable hot-swapping, work fine with 68-pin cables
External SCSI-1 = 50-pin centronics
External SCSI-2 = 50-pin HD DB
External SCSI-2 and 3 = 68-pin HD DB
External SCSI-2 = 25-pin (Macs and Zip Drives)

ISA SCSI controllers = 5 MBps PCI SCSI controllers = 132 MBps

Is possible to mix IDE/SCSI hard drives, IDE boots first unless set in BIOS otherwise

If SCSI Scan not run during boot process, make sure ROM BIOS on host adapter is on

[edit section] Chapter 20: Sound

Single Track (Monaural) or Two Tracks (stereo)

? CD quality = 44 KHz 16-bit depth, in stereo

Pulse Code Modulation (PCM): sound format, better known as WAV file format

Compressor/decompressor, aka CODEC,

best known being MP3 (MPEG-1 Layer 3 Codec)

MIDI: every sound card comes w/ a second processor designed to interpret standardized musical instrument digital interface, is a text file that uses sound processing hardware

? tiny in comparison to WAV files

? uses FM synthesis or wave table synthesis

FM Synthesis: electronic emulation of various instruments, sounds increasingly bad the farther up the scale you go

Wave Table Synthesis: embed sound recordings of actual instruments

Other File Formats: ASX (Streaming Audio), ASM/WMA (internet, streaming sound), RM(RealMedia), AIFF (Audio Interchange File Format, found on Macs, quicktime plays), MOD/VOC (obsolete), AU (popular Mac format)

Video: AVI (Audio Video Interleaves), MPEG (Moving Pictures Experts Group)

Streaming Media: played on your computer and then immediately discarded

Sound cards differ in five basic areas

1. Processor Capabilities - high end free CPU of processing sound, excellent sound

2. Speaker Support - better ones support 5 or more speakers, subwoofers, better ones support Dolby Digital/DTS/5.1 (5 speakers, 1 subwoofer)

3. Recording Quality - record with substantially less amount of noise/static, measured in signal-to-noise ratio, expressed in decibels

4. Jacks - stereo, microphone, and secondary output are standard jacks, joystick/MIDI devices (15-pin female DB)

5. Extra Features - firewire, immediate MP3 playing from MP3 player

Audio Cable: connect from sound card to CD drive, connector called MPC2

? older media players can use universal audio cables (since no standard existed)

Speaker Standards: Stereo (right/left speaker), 2.1 (two speakers (satellites), 1 subwoofer that connect into speakers), Surround Sound (five channels of sound, 1 subwoofer)

Direct X: games talk to Direct X and avoid OS, DirectX version 3 introduced DirectSound 3D (places sounds anywhere within 3D environment)

? used EAX extension

Installing a Sound Card

1. Snap card in securely

2. Screw in

3. Connect CD audio cable to CD/DVD media drive and CD Audio port on the sound card.

4. Install Driver (Plug and Play)

5. Check Device Manager

6. Configure in Sounds and Audio Devices applet (hardware tab lists all installed codecs)

[edit section] Chapter 21: Portable PCs

PC Cards: roughly credit-card sized, enhance and extend features of the Portable PC.

aka PCMCIA ? Personal Computer Memory Card International Association-are hot swappable/hot pluggable

Come in two flavors: Regular and Cardbus, and each come in three different sizes (Type 1, 2, and 3)

Regular: 5 volt, 16 bit, have up to two distinct function/devices

Cardbus: laptop must have Win 95 OSR2 or later to work

- Regular will fit into Cardbus slot, but not vice versa**

Type 1, 2, and 3 differ only in size/thickness (all share same 68-pin interface)

Ex) if there are two type 2 slots, can use 2 type 1 or 2 cards, or 1 type 3

PCMCIA: has two levels of software drivers, socket services (detect cards being inserted/removed) and card services (recognizes functions of cards inserted)

USB: comes in two flavors, USB 1.1 and USB 2.0 (MAX cable length 5 meters)

1.1 ? 12 Mbps

2.0 ? 480 Mbps, backwards compatible "High speed USB"

Port Replicators: plug into USB port, offers common PC ports (serial, parallel, USB, etc)

Docking Stations: similar to port replicators, often have DVD drive or PC Card slots

Older laptops use 72-pin or 144-pin SO-DIMMs with SDRAM technology

DDR SDRAM systems primarily use 200-pin SO-DIMMS

Hard Drives: 2.5 inch usually max of 80 GB, 3.5 up to 200 GB, no difference between the two

Modular Drives: replaceable CD-ROM, DVD-ROM, floppy, etc. Take one out and replace with another one.

Batteries

1. Nickel-Cadmium (NiCd): problem of battery memory, or battery losing significant part of its rechargeability if it was recharged repeatedly without being totally discharged. Lasted short time, had to be replaced, lose charge in heat, need to be disposed of in recycling services.

2. Nickel-Metal Hydride (Ni-MH): much less susceptible to memory problems, better tolerate overcharging, last longer between charging. Non-toxic to the environment, best to recharge with "shallow" recharges

3. Lithium Ion (LI-Ion): last twice as long as Ni-MH batteries, immune to memory problems, can't handle as many charges, will explode if overcharges, but contain circuitry to prevent that from happening

Store batteries in a cool place (freezer is a bad idea), condition Ni-Cd and Ni-MH cards by using a charger that also conditions the battery, keep contacts clean with a little alcohol and dry cloth, never handle ruptured battery, and recycle batteries.

For power management, features called System management mode (SMM) implemented in all laptops, needed unique BIOS to go with SMM CPU (Advanced Power Management, or APM, specification) and the (Advanced Configuration and Power Interface, or ACPI) standard

Requirement for APM/ACPI

1. SMM-capable CPU

2. APM-compliant BIOS

3. Energy-Star devices, or devices that will shut off

4. System's OS must know hot to request a device be shut down

? difference in ACPI is that it allows hot-swappable devices

Levels for APM/ACPI:

Full On (running at full power)

APM Enabled (CPU and RAM running at full power)

APM Standby (CPU stopped, RAM still stores programs)

APM Suspend (hibernation mode, everything stopped)

Configuring of APM/ACPI: Win 9x/Me = Display Applet

Win 200/XP = Power Options Applet

[edit section] Chapter 22: Printers

Modern printers break down into several different types, such as impact, inkjet, dye-sublimination, thermal, and laser printers.

Impact Printers

Creates an image by physically striking an ink ribbon cable against the paper's surface.

slow and noisy
use a grid, or matrix, of tiny pins to print image (much like monitor prints image on screen), direct contact from printwires to print
uses either 9 or 24 pins

Inkjet Printers

Ejects ink through tiny tubes, usually through heat (some do mechanically), uses electroconductive plates

Print Resolution: density of the ink, which affects print quality (measured in DPI)
Print Speed (measured in PPM, pages per minute)

Dye-Sublimation Printers

Used mainly for photo-printing, uses roll of heat-sensitive plastic film embedded with page-sized sections of CMYK (continuous tone, each pixel blend of the different colors)

Thermal Printers

Two types in use, Thermal Wax Transfer and direct thermal printer

Direct thermal use a heated print head, used as receipt printer
thermal wax melts wax onto paper, uses dithering so quality not as good

Laser Printers

Uses process called electro-photographic imaging,

1. The Toner Cartridge: supplies the toner that creates the image

2. The Photosensitive Drum: aluminum cylinder coated with photosensitive compounds

3. Erase Lamp: exposes entire surface of photosensitive drum to light

4. Primary Corona: never touches the drum, but is close to it, enables voltage to be passed to drum

5. Laser: acts as the writing mechanism for the printer

6. Toner: fine powder made up of plastic particles bonded to iron particles

7. Transfer Corona: paper given a charge that will attract the toner particles off the drum and onto the paper

8. Fuser Assembly: fuse (melt) the toner to the paper

9. Power Supplies: all laser printers have at least two power supplies, first called the primary power supply, provides power to motors that move the paper.

10. Turning Gears: broken up into discrete units generically called gear packs or gearboxes

11. System Board: main processor, printer's ROM, and RAM used to store the image before it is printed.

12. Ozone Filter: coronas inside generate ozone, needs to be vacuumed/replaced periodically

13. Sensor/Switches: used to detect a broad range of conditions such as paper jams, empty paper trays, or low toner levels.

The laser printing process:

Clean -> drum returned to clean, fresh condition (rubber cleaning blade), electrically cleaned as well
Charge -> to make drum receptive to new images, must be charged
Write -> laser used to write image to drum
Develop -> particles with lesser charge attracted, creates developed image
Transfer -> transfer from the drum to the paper
Fuse -> particles fused (melted) to the paper (passed through two rollers)

Printer Languages: ASCII control codes, PostScript (defines the page as a single raster image), PCL (Hewlitt Packard's Printer Control Language), Windows GDI (graphical Device Interface, uses CPU rather than printer to process a print job)

Printer Connectivity

Parallel cable connections
Network connections
USB
Serial
Infrared

Parallel uses cable, which attaches to computer through male DB-25 and to the printer through a male 36-pin Centronics connector. Most parallel cables no longer than 10 feet, crosstalk could occur if longer (electrical interference) 150 KBps

IEEE 1284 Standard (parallel cable and printers conform to these standards)

1. Compatibility Mode: backward compatibility

2. Nibble Mode: allows printer to send information back to the computer, in two four bit chunks (nibbles)

3. Byte Mode: allows the printer to communicate with the computer at the same rate the computer speaks with the printer

4. Enhanced Capability Port (ECP): bidirectional mode for fast communications between computer and any device attached to parallel ports

5. Enhanced Parallel Port Mode: provide common interface for devices besides printers that require speed (scanners, external hard drives, etc)

Serial cable uses 9-pin or 25-pin connector, only one bit at a time, advantage is longer cable length (25 feet)

Network cable connections: dedicated print server not needed, network printer is available all the time, uses RJ-45 connection

USB: plug and play, no need to configure ports, IRQs, DMA channels

Infrared: need an infrared transmitter/receiver,

Windows 9x System Printing

Print Job -> print spooler + print driver (work together to format print job in language the printer can understand) -> printer

Windows 2000/XP Printing

A "printer" is not a device, but rather a program that controls one or more printers. Physical printer called a "print device", provides for amazing flexibility (act as print server)

Setting Up Printers: Start | Control Panel | Printer and Faxes (Win XP)

Settings | Printers (Win 9x/Me and 2000)

Troubleshooting Printers

1. Print Job Never Prints: printer on? connected? online? does it have paper?, check print status otherwise

2. Strange Size: usually points to user mistake in setting up the print job

3. Misaligned or Garbage Prints: corrupted/incorrect driver, uninstall and reinstall the driver

4. Dealing with Consumables: paper, ribbons, ink cartridges, never throw away toner cartridges

5. Check the MSDS: check with Material Safety Data Sheet

6. Crashes on Power Up: reverse power-up, turn on printer before PC to avoid both needing their peak loads simultaneously

Troubleshooting Dot-Matrix Printers

1. Bad-Looking text: try cleaning printhead with denatured alcohol, otherwise replace printhead

2. Bad-Looking Page: if page covered with dots and small smudges, the platen is dirty

Troubleshooting Inkjet Printer

? generally have built-in maintenance programs to use

Laser Printer Maintenance: can of pressurized air outside, or Low static vacuum inside

Laser Printer Problems

1. Blank Paper: out of toner, print diagnostic page if toner is there

2. Dirty Printouts: get the printer cleaned (fusing mechanism gets dirty)

3. Ghosting: imaging drum not fully discharged, cleaning blade worn-off

4. Black Paper: drum is not being charged. The primary corona is broken or not making good electrical contact.

5. Toner Falls off Paper: Fuser assembly is malfunctioning and is not binding toner to the paper.

[edit section] Chapter 23: Networking

Data moved within network in packets or frames, NIC needed (unique ID)

? ID called MAC Address, or Media-Access Control address

(48 bits long, represent using 12 hexadecimal digits)

To send, need sender and recipient's MAC address, data, and data check (Cyclic Redundancy Code, or CRC)

Two modern protocols used today, Ethernet and Token Ring

? Ethernet comes in Coaxial cable, unshielded twisted pair, and fiber optic

Bus topology: voltage bounces back at end of wire, packets reflect and create packet storms. To prevent this, a terminator must be plugged in (nothing more than a resistor that absorbs the signal).

Coaxial Ethernet

-cable within a cable, center core surrounded by insulation, inner core carries signal, outer core shields from outside interference

Thick Ethernet - 10Base5: thick (half an inch) coaxial called RG-8 (Radio Grade)

the "10" means that data transfer is a maximum 10 Mbps, 5 stands for 500 meter max length. Up to 100 devices to one segment (bus topology). All devices must be connected at the "marks" on the cable (multiples of 2.5 meters), connects through a vampire connector (actually pierces the cable), cable from connector to device no longer than 50 meters. Uses 50-ohm terminator, connects via 15-pin DB connector

Thin Ethernet - 10Base2: uses Rg-58, looks similar to cable on television, aka "Thinnet" or "802.3" , 10 Mbps, supports only 30 devices per segment, segments no longer than 185 meters long, Thinnet network card connected to bus cable with T connector, has twist-on connectors (BNC connectors), one of the terminators must be grounded

UTP Ethernet (10*BaseT): 10BaseT, 100BaseT, or 1000BaseT, use star topology, connect with unshielded twisted pair (UTP). Max distance from hub to device is 100 meters.

? UTP cables come in categories that define the max bandwidth

CAT1	Standard Phone Line
CAT 2	4 Mbps (ISDN and T1)
CAT 3	16 Mbps
CAT 4	20 Mbps
CAT 5	100 Mbps
CAT 5e	1 Gbps
CAT 6	10 Gbps

? Predominantly using CAT 5, 5e, and 6

Implementing 10^xBaseT: 10BaseT needs CAT 3,4, or 5. 100BaseT needs at least CAT5, 1000BaseT needs CAT 5e or CAT 6.

Pin	568A	568B
1	White/Green	White/Orange
8	Brown	Brown

PVC vs Plenum fire ratings: PVC can burn and create noxious fumes, use Plenum

Crossover Cables: hook 10Base^xT network cards together without a hub, one end uses RJ-45 568A standard, the other end uses 568B standard, thus reversing the signal

Auto-sensing: accommodates for half-duplex devices

Fiber Optic Ethernet

immune to electrical problems, travel much farther (2,000 meters)

-	LED used, multimode fiber optic cabling (uses different reflection angles)

- single mode uses laser light, currently quite rare (fast data transfer and long distance)

- two most common standards are 10BaseFL and 100BaseFX (difference is speed)

Token Ring

- use a ring topology, incompatible with Ethernet

- use transmission method called token passing, mini-packet called a token passes from one NIC to the next around the ring, PC wanting to send data must hold packet before it can do so.

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Ultimate Comtia A+ Certification Study Guide

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Contents

[edit section] Introduction & Acknowledgements

[edit section] Chapter 2: The Visible PC

[edit section] Chapter 3: Microprocessors

[edit section] Chapter 4: RAM

[edit section] Chapter 5: BIOS and CMOS

[edit section] Chapter 6: Expansion Bus

[edit section] Chapter 7: Motherboards

[edit section] Chapter 8: Power Supplies

[edit section] Chapter 9: Floppy Drives

[edit section] Chapter 10: Hard Drive Technologies

[edit section] Chapter 11: Implementing Hard Drives

[edit section] Chapter 12: Understanding Windows

[edit section] Chapter 14: Installing and Upgrading Windows

[edit section] Chapter 15: Windows 9x and Windows Me

[edit section] Chapter 16: Windows NT, 2000, and XP

[edit section] Chapter 17: CD and DVD Media

[edit section] Chapter 18: Video

[edit section] Chapter 19: SCSI

[edit section] Chapter 20: Sound

[edit section] Chapter 21: Portable PCs

[edit section] Chapter 22: Printers

[edit section] Chapter 23: Networking

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