A+

Ports

0-1023 well-known; 1024 -49151 registered, 49152-65535 = free to be used by application vendors.

:: (IPv6)

0.0.0.0 in IPv4 equivalent. Usualy means host is not configured.

laser print process:

1. store pagr in memory 2.-600VDC charge on photsensitive drum 3. laser paints image, discharging image areas to low -100VDC 4. Devloping rolller in toner cartridge has -600VDC toner stuck. as rollls towards photosensitive drum, toner sticks to areas laser discharged. 5. image transferred from drum to paper at its line of contact by means of the transfer corona wire or roller with a +600VDC charge. the static eliminator strip removes the high, positive charge from the paper, which has the image and moves on. 6. paper enters fuser, where fuser roller and pressure roller make the image permanent. 7. paper exits printer, printer uses rubber scraper to clean the photosensitive drum.

PCIe versions

1.x 2.x 3.0 and 4.0. Single lane data rates of 250, 500, 1000, and 2000 MBps

UTP cat 6

10 Gbps but only up to a distance of 55 meters.

UTP cat 6a

10 Gbps up to 100m

Utp cat 5

100Mbps

ethernet naming standards

10Base2 = 10 refers to maximum speed the standard supports, 10Mbps in this case. Base = type of transmission (baseband or broadband), 5 or 2 = approximate max transmission distance in hundreds of meters. T stands for twisted pair cabling.

multimode fiber

10Gbps for up to 550 meters (1,804 ft, 1/3 mile). allows multiple modes (paths) of light to propagate simultaneously. light bounces off the cable walls as it travels through the cable, which causes to weaken more quickly. used as a "horizontal cable". delivers more available bandwidth (but shortens the cable distances). Use light-emmitting diodes (LEDs) to generate the light. Lasers also used in higher-bandwidth network devices such as Gigabit Ethernet.

802.11b

11Mbps (fallback rates of 5.5, 2, 1Mbps.) 2.4 GHz range. uses DSSS. relatively uncommon today.

IPv6

128 bit addresses. running out of IPv4 addresses- IPv6 provides 3.4x10^38 addresses. hexadecimal notation. eight fields of four hex characters /16-bit fields (16 bytes). Unicast, anycast, multicast addresses. Global prefix: first 3 2-byte fields. Subnet: 4th 2-byte field; interface ID: last 4 2-byte fields.

Max capacity of drive

128 pb (pb = 1024 tb)

SXGA+

1400x1050

DIX or DB15 connector

15-pin AUI connector that connects to vampire tap / thicknet cable connection.

CD ROM speed

150 KBps = 1x. 2x - 8x, which was max speed before danger of discs spinning apart. 16x, 32x, etc is only theoretical max transfer rates. 52x Max. Aren't spinning faster, but improvements in electronics and buffering = higher transfer rates.

MicroSD

15mm x 11mm

WSXGA+

16:10, 1680x1050

WUXGA

16:10, 1920x1200

WQXGA

16:10, 2560x1600

WQUXGA

16:10, 3840x2400

WHUXGA

16:10, 7680x4800

ATSC 720p

16:9, 1280x720

ATSC 1080i/p

16:9, 1920x1080

UTP cat 4

16Mbps

DIMM for DDR

184 pins and single keying notch

UTP cat 5e

1Gbps. four twisted pairs of copper wire are physically separated and contain more twists per foot than cat 5.

DVD ROM speed

1x = 1.4 MBps. 16x common.

BLU RAY speed

1x = 4.5 MBps. 2x speeds play commercial videos properly.

Intel core 2

2 doesn't imply 2 cores. 2nd gen of core processors for mobile; based on core architecture (how Intel markets microcode of certain processors)

wireless channels

2.4GHz- need to be five numbers apart to not overlap. 11 configurable channels. 5GHz- choose from 20MHz or 40MHz channels, cannot overlap. possible to manually set in wireless router settings when you need to set up two or more wireless access points. set up overlapping ranges, at least 10% and up to 20%. configure the WAPs with the same SSID. configure the WAPs with non-overlapping channels.

ATX12V 2.1

20 pin connector + Gives dedicated power to PCIe adapters. 6 pin PCIe connector... 75w

QXGA

2048x1536

Truecolor

24-bit palettes made up of almost 17 million colors, near the number the human eye can distinguish

DIMM for DDR2

240 pins and one keying notch and possibly aluminum cover (heat spreader) for both sides.

number of networks available

2^n (n represents the num of bits being used.) Class A = 2^7, 128. 0 and 127 reserved, so really 126.

number of hosts available

2^n-2 (broadcast and network address)

SATA power connectors

3 +3.3V, +5V, and +12V leads interleaved with two sets of 3 ground leads.

IPv4 address

32-bit hierarchical (nums at beginning of address identify roups of computers that belong to same network) address that identifies host on network. dotted-decimal notation. each numbers represents 8 bits (1 byte) known as octet. Al numbers between 0 and 255. 128, 64, 32, 16, 8, 4, 2, 1

PCI slot

32-bit peripheral component interconnect. 3" long, classically white. Operate at 33mhz or 66mhz over 32-bit channel, resulting in 133MBps or 266MBps data rates. 3.3v (notch near rear) and 5v (notch near front) also universal (both notches) versions.

UHD 4K

3840x2160

4G

4th generation Long Term Evolution. faster than 3G. 10 to 20Mbps download 3-10Mbps upload. theoretical max speed 300Mbps down 75Mbps up. designed to use IP instead of traditional telephone circuits for mobile broadband access. WiMax and LTE are the competing 4G standards.

e-readers

6" touchscreen, 2GB to 4GB storage, Wi-FI connectivity, 6-8oz.

Mini-ITX

6.7"x6.7". Rear interfaces same location as on ATX, compatible. Used in embedded systems and lack requisite mounting and interface specs.

plasma display

600 Hz refresh rate for fluid video motion. plasma refers to a cloud of ionized (charged) particles-- atoms and molecules with electrons in an unstable state. electrical imbalance throws off light as the particles achieve balance. running current through inert gas. more in common with cathode ray tubes (CRTs- legacy). No backlight required. phosphors can be used up over time, or burn images into the screen.

ATSC 480i/480p 4:3 or 16:9

704x480 (colors not specified)

Socket FM2

AMD only, 904 pin desktop socket for trinity and Richland APUs.

Socket FM2+

AMD only, 906 pin desktop socket for steamroller based APUs Kaveri and Godavari. Accepts chips that fit FM2, reverse is not true.

Socket FM1

AMD only. Accepts fusion accelerated processing units (APUs) for desktops, which incorporate cpus and gpus. E.g. Early Aseroes APUs.

Socket AM3+

AMD only. CPUs based on bulldozer architecture.

Socket AM3

AMD only. DDR3 capable CPUs only

ATSC standard

Advanced Television Systems Committee standard for widescreen aspect ratios is 16:9 (1.778). Popular 1920x1200 (16:10) computer monitors being replaced with 1920x1080, 16:9 resolution.

LoJack

Allows computing devices to be electronically tracked and controlled through persistence. Many laptop vendors incorporate LoJack code and persistence and not all incorporate the ability to disable it.

Power connector

Allows mb to be connected to power supply. WhereATX power connector plugs in.

KVM switch

Allows you to switch between input/output devices and allows you to have multiple systems attached to same Keyboard, video, mouse. Select the switch that accommodates the type of interfaces I/O devices require, e.g. Mini-DIN, USB, VGA, DVI.

Cellular card

Almost every cellular service provider offers a line of adapters that can be installed into/inserted on the outside of computer. Some have modified access points to allow the insertion of such adapters into USB interface to act as WAN gateway.

Buffered memory

Also, registered memory. Buffer is temp storage area that takes some of the load off the primary circuit. Unbuffered/unregistered memory does not have these hardware registers.

Heat spreader

Aluminum cover that dissipates heat away from the memory chips

Component video

Analog video: Split red, green, and blue signals at the source for better quality. One uncompressed and two compressed signals, which means less bandwidth than RGB separation. Uncompressed signal is called la (y) which is colorless and represents the "brightness" of the image . Pb and Pr (chrominance) signals are B-Y and R-Y, subtracting out luma. YPbPR is another way to refer to this technology . Capable of transmitting HD 1080p, as long as video source is capable of pushing that resolution over component outputs.

passive matrix (pixel addressing)

Angles of visibility and speed are worse. neighboring pixels can be affected, resulting in muddy/crosstalk. does not have a dedicated transistor or each pixel or subpixel. instead, matrix of conductive traces. when the display is instructed to change the crystalline alignment of a particular pixel, it sends a signal across the x- and y- coordinate traces that intersect at that pixel, turning it on.

Firmware

Any software encoded in hardware. Usually ROM chip. Best example: BIOS

Power supply exhaust fan

At back of power supply. Draws air from inside case into vents in power supply. Pulls hot air through power supply and out exhaust

Recordable discs/burners

At standard power, laser reads discs. By increasing the power, the laser could write to disc. Eventually writable/re-writable discs developed. Third level of power (in between first two) could neutralize the crystalline material. Two types of disc erasure: erase total disc before new material written, or data can be erased on the fly by one laser before second laser writes new material.

Smart card reader

Attached internally or externally through USB . Reads chips embedded in cards. Chips contain combo of rom, prom, ram, and a 16-bit CPU. May contain one or more pki certificates .

APIPA (zero configuration networking or address auto-configuration)

Automatic Private IP Addressing. TCP/IP standard used to automatically configure IP based hosts that are unable to reach a DHCP server. APIPA addresses in the 169.254.0.0 range w subnet mask of 255.255.0.0. If you see one of these addresses, you know computer configured itself. continues to broadcast for DHCP server so that it can be given a real address.

BGA

Ball grid array. May have embedded heat slug. Used for most integrated apps.

BIOS

Basic input output system. Contains software that boots system and allows os to interact with certain hardware. Usually easily identifiable; newer boards it may be incorporated into the southbridge. Performs POST.

Optical drives

Blu ray disk, digital versatile disc, compact disk drive. Encoding schemes used to store data are incompatible with schemes used to record audio and video to same disk. 5 1/4" drives, 12cm disk.

Hard drive cooling

Both active and passive devices available. Active cooling bay most common. Install hard drive in device that fits in 5'QF" expansion bay, device contains fans. Heat sinks also available.

Front intake fan

Brings fresh cool air into computer

Smart TV

Built in system for accessing network devices.

Integrated components

Built into motherboard. Don't need an adapter, but still need correct drivers.

Internal cache

Built into processor's silicon wafer (L1)

Parallel connectivity

Bus architecture. Multiple synchronized wires or traces... Slower bc separate lines need to be synchronized, also shorter circuit length and less throughput than serial connectivity.

Recordable CD format

CD-R or CD-RW. CD-r can write only once; RW multiple times. Format : write-rewrite-read speed. 52x-32x-52x

Air cooling

CPU fan blows air down the body of heat sink. Sometimes placed at right angle. Best fans are high CFM (cubic feet per minute). Thermal transfer compound for where CPU touches heat sink to avoid super heated pockets of air.

CPU cooling

CPU generates more heat than any other component. Most motherboards have an internal CPU heat sensor and CPU_FAN sensor. Different methods include: air cooling, liquid cooling, fabless/passive cooling.

802.3

CSMA/CD (Ethernet) LAN. Original standard defines a bus topology network that uses 50-ohm coaxial baseband cable and carries transmissions at 10Mbps. uses Carrier Sense Multiple Access with Collision Detection cable access method to put data on the cable. Now, 10Gbps.

contention based access

CSMA/CD considered contention based access method.

RG-59

Cable television. Less popular coax. one of two coax cable types in use today. considered adequate for analog cable tv but not digital. max distance 228 m (750 ft). max speed depends on quality of cable. 75 ohms impedance

External cache

Cache memory on the motherboard (L2)

Video capture card

Can be stand alone device; used to save video stream to computer for later manipulation.

Barcode reader/ scanner

Can use LEDs or lasers as light sources and can scan one- or two-dimensional codes. USB connection common. Classic interfaces used a splitter to connect to keyboards connection, so the barcode scanner input was recognized as keyboard input. Smartphone cameras can act as scanners for 2-dimensional UPC and QR codes.

DRAM based ssd

Can use as much power as HDD, able to modules can be upgraded, making larger ssd . Faster than flash ssd.

HDMI

Carries both audio and video; only CATV coaxial connections to tv card can do that on PC.

I/O card

Catch all phrase for any card that enhances the system. Common examples: usb cards, FireWire cards, thunderbolt cards, storage cards (sata). Usually plug n play.

Single sided memory

Chips on only one side. No switching of memory controller required.

Chipset cooling

Chipset/chip controls how comp operates; when you overclock a computer, the chipset may need to be cooled by more than ambient air.

Expansion / adapter card

Circuit board that you install into a computer to increase the capabilities. Card being installed must match the bus type of the motherboard. Four most common: video, multimedia, I/O, communications.

AT system connector

Classic Power connector. Two six-wire connectors (p8 and p9) that connect to AT style motherboard.

Cpu speed

Clock frequency; crystal (xtl) keeps the time for the flow of data on the motherboard

Composite video

Combines all luma and chroma leads into one- least quality for analog video. National Television System Committee (NTSC) signal recieved by over-the-air antennas or cable tv feeds is composite video. Cost efficient, but low quality. Single Yellow RCA jack. Cable that has three leads- red white (left and right audio) and yellow (composite video).

RAID 5

Combines benefits of 1 and 0 by creating a redundant striped volume set. Does not employ mirroring for redundancy. Parity interleaved across all drives. Minimum of 3 drives required. (One drive is lost for parity). Lose two disks, lose function.

CIFS

Common Internet File System. MS dev'd enhancement of the SMB protocol. Which was also developed by MS. the intent behind CIFS is that it can be used to share files and printers between computers. Default file and print sharing protocol on Windows-based computers since windows 2000.

CD-ROM

Compact disc. Designed for long term data storage. 650mb in earliest format; 700,800,900 Mbps versions common.

Micro ATX

Compatible w standard ATX cases, as well as smaller. Same component placement. Less memory slots, motherboard headers, expansion slots etc. 9.6"x9.6" (244mm)

CMOS

Complimentary metal oxide semiconductor memory chip. Stores information/settings such as security settings, memory, cpu settings, etc. even when the computer is powered off. Bios reads info from cmos such as which hard drives are configured for computer to use, which drives to search for boot sectors etc. overlapping info defailults to bios.

Tracks

Concentric rings around platters. Drawn magnetically. (Hard drive)

Hard disk connectors

Connection from hard disk to motherboard; onboard/off-board; known as drive interfaces. Consists of circuitry, port/header. Most are SATA.

Webcam

Connects directly to computer through I/o interface such as USB or WiFi. No self-contained recording mechanism.

Controller

Controller chip controls how drive operates and how data is encoded into platters, sends signals to various motors inside drive, receives signals from sensors inside drive. (Most common SATA)

Role of CPU

Controls and directs all activities of computer using both internal/external buses

Power supply

Converts 110 or 220 ac into DC voltage computer needs to operate. +3.3vdc , +5vdc, -5vdc, +12vdc, -12vdc. (Direct current)

Sound card

Converts computer signals to sound. Common integrated device. Typically has small 1/8" jack for connecting micro/headphones, speakers, etc. many used to have DA15 game port. Today might come with RCA jack (digital audio specification known as Sony/Phillips Digital interface ... For digital clarity).

Microphone

Converts sound waves into varying electrical signals classic analog pink TRS connector or USB. Configuration often done through sound applet in control panel.

Phase-change cooling

Cooling effect of change from liquid to gas used to cool inside of computer. Expensive! Air conditioner like pumps send coolant to heat sink blocks on CPU. Noisiest method. Condensation a problem.

Cpu fan

Cools processor, typically attached to large heat sink

Device connector types

D-subminiature, RJ-series, others

D-subminiature Connectors

DXn, where X is replaced by A through E, denoting size of connector. N replaced by the number of pins or sockets in the connector. D shape (trapezoid) ensures only one orientation possible.

DEP

Data execution prevention. OS level no-execute bit support for Windows. First introduced with Windows xp.

DOCSIS

Data over cable service internet specification.

Sector

Delineation within track on platters in hard drive. Magnetic drive sectors store 512 bytes (.5 kb) data. BIOS supports 63 sectors per track, but hard drives can have more. Controller must translate directions to bios.

ATX12v

Designed to get more varied power to system board. Added two supplemental connectors. Versions include single 6 pin auxiliary connector similar to p8/p9 AT connector. 4 pin square version of ATX connector (P4) also included

ITX

Dev'd by VIA. Low power, small form factor (SFF). Specialty use (home-theater, embedded components). Consists of mini-ITX (6.7"x6.7") , Nano-ITX (4.7"x4.7") , Pico-ITX (3.9"x2.8") , Mobile-ITX (2.4"x2.4")

Dual- triple-channel memory

Developed to relieve bottleneck between cpu and ram. Memory controllers coordinate 2/3 memory banks to work as synchronized set during comms with cpu, doubling/tripling specified system bus width from memory perspective.

Warm swappable

Devices that have a file system and need to use safely remove hardware utility.

Thunderbolt

Digital , combines x4 PCIe 2.0 with DisplayPort 1.x technology. Copper powered cable extending as far as 3m, designed to be less expensive than active DisplayPort cable. Optical cables can extend as far as 60 m, terminate in copper MDP connector. Data interface: v1 and v2 20Gbps, 18V and 9.9W of power total. Can be daisy chained and connected via hubs, like USB and FireWire.

DRM

Digital rights management. Series of technologies protecting against piracy. Graphics display standards such as HDMI, DVI, DisplayPort support one or more. DisplayPort Content Protection (DPCP) or High Bandwidth Digital Content Protection HDCP, which encrypts media.

DVD-ROM

Digital versatile/video disk . Basic version: single-sided disc with single layer of encoded information. 4.7GB. Double sided disc: 9.4GB. (This capacity isn't actually realized when two layers placed on same side of disk. Space between layers is 10% wider to facilitate burning layer without affecting another. 90% remaining capacity per layer: 8.5GB.) . Red laser wavelength (780nm).

DVI connector

Digital video/visual interface. Developed to move from analog to digital video, which can be transmitted farther at higher quality. Looks like D-sub connector but has many pins arranged asymmetrically. 3 types: DVI-A (analog only connecto), DVI-D (single or dual link, digital only), DVI-I (combo-source and monitor must both support same the same technology, either analog or digital)

RAID 1

Disk mirroring. Producing fault tolerance by writing all data simultaneously to two separate drives. If one fails, data is still on second. Doesn't improve speed, increases costs.

RAID 0

Disk striping. Striped set of equal space from at least two drives creates larger volume. One drive can be reading or writing while another drives read-write head is moving. Doesn't provide fault tolerance (not really redundant).

DDR SDRAM

Doubles the data transfer rate of traditional SDRAM by double pumping data. Transfers a bit per pin on both rise and fall of clock signal. FSB clock signal x 2 x data bus width (normally 64-bit or 8 byte processor)

DIMM

Dual inline memory module. Differ in number of conductors/pins. Common: 168-, 184-, 240- pin configurations

DIMM

Dual inline memory module. Used as package for SDRAM family: SDR, DDR, DDR2, DDR3. Dual differentiates the functionality of the pins on one side of the module with the corresponding pins on the other side. Eg- 84 pins on each side = 168 pins on each

DIP

Dual inline package. Legacy

DIP form factor

Dual inline package: before 1981. Rectangular w two rows of 20 pins. Now CPUs use LGA.

DVD-DL

Dvd dual layer. Two layers placed on same side of disc. 8.5 gb. Add double sided disk: 17.1 GB. Red laser wavelength (650nm)

DRAM

Dynamic random access memory. Use dram to expand memory in computer. Dynamic refers to chips' need for constant update signal to keep info written there. Most popular are synchronous- DDR, DDR2, and DDR3.

electrophoretic ink

E ink. E-readers. use lower energy tan other lcd displays, greatly prolonging battery life. easy to read in bright conditions.

HVPS - laser printer

EP process requires high-voltage electricity (high voltage power supply). This component converts AC from a standard wall outlet (120V and 60Hz) into higher voltages a printer can use. Energizes the charging corona and transfer corona.

Riser card

Expansion card slots placed sideways to maximize vertical space (NLX motherboard... New Low-Profile Extended).

Video adapter cards

Expansion card to allow the comp to display info to a monitor. Converts data from CPU into pixels addresses etc required for display. Basic video cards with PCIE interface operate sufficiently, but AGP and PCIe- offer more resources to adapter. PCIe preferred.

XGA

Extended Graphics Array. Resolutions: 800x600 (65,536 colors) or 1024x768 (256 colors)

System data bus

External bus of cpu . Width dictates how many memory chips or modules required to satisfy bank.

2.4 GHz wireless networking channels

FCC has defined 14 different 22MHz comms channels. Only allowed to configure your wireless networking devices to the first 11. multiple overlapping wireless access points: need to have non-overlapping channels to avoid communications problems.

Memory module fan

Faster memory runs hotter; may require cooling

PCIe

Faster than AGP with flexibility of PCI. PCIe not compatible with AGP or PCI. Referred to as a bus architecture, but more like a star. Buses share total bandwidth among all slots, PCIe uses lanes- switched point-to point signal paths between any two PCIe components.

IEEE 1394

FireWire. 6 / 4 pin port. Isynchronous (synchronized clock) mode, 400 Mbps to 3.2 Gbps transfer speed. Often used to get digital video into pc for editing. High power output, reducing the need for external power

Modem

For computers that connect to Internet through Analog dial-up connection. Modulator/demodulator. Converts digital signals from computer to send analog signals over phone lines. One connector for expansion bus being used, one connector for telephone line. (RJ-11)

Graphic and CAD/CAM design workstation

For designers of graphical content, engineers, architects, etc. CPU enhancements, Video enhancements, Maximized RAM. These systems put quite a load on CPUs- best type of CPU will be a muilticore processor. Each core can execute instructions independently. Sufficient cache memory is important, too- each core should have significant L1/L2 dedicated to it, shared L3. CNC computerized numerical control systems take coded instructions from computer and render them into machine or tool movements. Requires Graphics Adapters with better GPUs and additional RAM on board.

sending and controlling data (NIC)

For two comps to send and receive data, the NICs must agree on : maximum size of data frames, amt of dat sent before giving confirmation, time needed btwn transmissions, amt of time to wait before sending confirmation, speed at which data transmits.

Active memory cooling

Forcing some kind of cooling medium (air or water) around the ram chips themselves or heat sinks

cellular WAN

GSM and CDMA cell standards; 4GLTE latest technology. 3.1 miles cell size. reasonable performance for 19mi.

Standard peripheral power connector/ molex

Generally used to power types of internal disk drives. Also known as molex connector.

Communications adapter

Give ability to transmit data to devices that might be too distant to cable up to directly. Network adapters and modems two most popular types. NIC used within administrative domain of a home or enterprise to rely on other devices to relay transmissions around world. Modems allow direct domestic/international communication between two devices across pstn.

2000::/3

Global unicast address range for use on the internet

Integrated gpu

Graphics processing unit. Integrated into cpu. Take much of the burden off cpu itself.

Allocation units/ clusters

Group of sectors - concept exists bc there is a finite number of bits to address units of storage. Volumes based on master boot record are limited to 2 TB. No two files can copy to the same cluster, results in a waste of space that defragmenting cannot correct. The larger the cluster size, the larger the waste.

TouchFLO

HTC touchscreen software. Now HTC Sense. in use today on Android and Windows lines of mobile devices. Not multi-touch capable. introduced an interface that the user perceives as multiple screenscombined with multi-touch.

Hyperthreading

HTT. Form of simultaneous multithreading (smt). Takes advantage of cpu's superscalar architecture. Processors can have multiple instructions operating on separate data in parallel. Appear to the OS as two processors

virtualization workstations

Hardware virtualization very popular, core technology that enables cloud computing. enables minimizing hardware footprint. Software development environment - developers need to ensure that their programs work on different operating systems. Important shared resources: CPU, system memory, drive storage space, system wide network bandwidth. Maximizing RAM important- hinges on three constraints: CPU's address-bus width, the host OS maximum supported RAM, the motherboard's max supported RAM. Server versions of OS and x64 over x86 versions of OS.

Double-sided memory

Has chips on both sides (as opposed to only one side). Treated by system as two memory modules. Memory controllers on motherboard must switch between the two sides, only accessing one side at a time. Store twice the memory in the same space

Ceramic leafless chip carrier

Has no leads, rounded pins through edge of ceramic or molded plastic pkg

Chipset fan

Heat sink / fan combo on advanced chipset

HGC

Hercules Graphics Card. resolutions: 720x350. Mono. (text and graphics).

HDMI

High-definition multimedia interface. All digital. Standard and high-speed HDMI cables- standard: 720p and 1080i resolution; high-speed : 1080p, 4K and 3D. HDMI version 1.4- capability for the controlling system to relay Ethernet frames between connected component and Internet, 3D support, 4K resolution (30Hz refresh rates) , 120Hz rate for 1080 resolutions, audio return channel (ARC). Version 2.0- increasing 4K refresh rate to 60Hz, 21:9 aspect ratio, 32-channel audio, but no new cable requirements. Version 2.0a added High Dynamic Range video (HDR), also does not require new cables.HDMI type-C = mini HDMI (19 pins) type B : 29 pins , type D : microHDMI, 19 pins. Passive HDMI cables: 15 m, active HDMI cables with electronics within cable: 30 m.

CPU socket

Hold cpu; pin grid array (pga) land grid array (lga)

Pin grid array

Holes and pins in row/column orientation. Older technology. Pins on motherboard, holes on processor. Zero insertion force (ZIF) sockets popular.

HBA

Host bus adapter. Translator. Converts signals from controller to signals that the computer understands.

VGA

IBM introduced with PS/2 line of computers. Analog technology, which is unlike other technologies (MDA, CGA, EGA, HDMI, DVI-D). technically, the electronics of all graphics adapters and monitors operate in the digital realm, but VGA graphics adapters output and monitors receive an analog signal over cable. Builds a dynamic palette of 256 colors, chosen from various shades and hues of an 18-bit palette of 262,114 colors. 256KB of video memory on board and could display 16 colors at 640x480, 640x350, 320x200 pixels. OR using mode 13h of the VGA BIOS, 256 colors at 320x200 pixels.

Internet layer (network)

ICMP, ARP, RARP, IP

IEEE 802 standards

IEEE developed standards for network types. Specify certain types of networks, although not every network protocol is covered by the IEEE 802 committee specs.

B channel

ISDN bearer channel- data is carried

D channel

ISDN signal channel- call setup and link management

Flashing the bios

If hardware upgrade is not recognized and there are no drivers to install, flashing the bios may be necessary. Replaces the burned-in code on the bios itself. Loss of power during this process is catastrophic on older systems. Most newer systems have fail-safes. Check motherboard manufacturer for code, not bios manufacturer.

Dual-drive solutions

Implemented as two separate drives - one HDD one ssd, so the user can choose where to store their data.

Cache memory

Improves speed (not amount of memory). Predicts what the cpu will ask for next.

EPS12V

In addition to 20 pin connector, Uses 8 pin version of mini ATX connector called processor power connector with four +12V leads and four grounds.

Mark/space parity

In systems that want to see 9 bits for every byte. Mark: 9th bit always 1, space: always 0. Less error detection bc only changes in parity bit detected.

LCD panel construction- IPS

In-plane switching. more expensive, slower response, more accurate, less reaction to touch, wider viewing angle, more power required. electrodes positioned parallel to one another on the same side of the liquid crystal panel, creating an electrical switch in the same plane. turning electrodes on results in a parallel alignment of the crystals lengthwise from one electrode to the other. light passes by the stack of crystals without twisting. reproduces colors more accurately and does not shift color when viewed at wide angles. Don't react when touched. Best for touch screens.

Touchscreen

Input/output device. Converts stimuli of some sort to electrical impulses that travel over serial connections to computer system. Resistive have to be controlled by fingernail or stylus. Capacitative- pad of finger. Installing touch screen entails attachment to the graphics adapter and serial interface. Most popular is USB port.

ATX motherboard

Intel developed in 90's, still most popular. 12"x9.6" (305mm x 244mm). Processor and memory in line with fan, runs cooler. Can install full length expansion cards.

Pentium M chip

Intel. Chipset that has built-in wireless networking: Has 3 components: Mobile Intel Express Chipset (graphics memory controller hub), Intel/PRO wireless Network Connection (handles integrated wireless LAN connection, Intel Centrino chipset, which is the brain of the chipset

Tv tuner card

Internal and external devices that allow you to connect to a broadcast signal. Analog/digital/hybrid varieties.

ICMP

Internet Control Message Protocol. Delivers error message, ping utility utilized to send and receive packets.

IP

Internet protocol. main workhorse of TCP/IP. responsible for managing logical network addresses and ultimately getting data from point A to point B. Three support protocols: ICMP, ARP, RARP.

PS/2 port

Keyboard/mouse. Also known as mini-DIN connector. Round with 3 notches; keyboard usually purple and mouse usually green.

backlight - laptops

LCD displays do not produce light, so backlight needed to generate brightness. Typical laptop uses cold cathode fluorescent lamp (CCFL). Requires an inverter (small circuit board behind the LCD panel that takes DC current and inverts to AC for the backlight. Inverters can discharge energy when you are working with them- be careful!

native resolution

LCD, plasma, OLED, and other flat panel displays have single fixed resolution, known as native resolution, which is unlike CRT monitors which can display images at many resolutions within supported range. native resolution comes from the placement of the transistors in the hardware display matrix of the monitor.

Connecting keyboards/mouse

Legacy AT connector (round with 5 pin configuration). PS/2 connector is a smaller 6 pin mini-DIN connector- purple for keyboard green for mouse. USB - connections for keyboards taking over.

Infrared port

Legacy, used Electromagnetic radiation in the infrared band to send and receive data (older but similar concept to Bluetooth). Very slow; Max speeds 16 Mbps. Line of sight only, typically 4 meter distance max.

Hercules Graphics Card

Legacy- pre-VGA, important thing to know is that it was the first graphics card that could display graphics as well as text, switching between text mode (predrawn characters from library) to graphics mode (optimized the adapter for drawing individual pixels) on the fly. all graphics card from there on out use the same concept.

Asynchronous DRAM

Legacy. Independent from CPUs internal clock. Have codes on them that end in a numerical value that is related to (usually 1/10 of) the access time of memory. Usually 40 - 120 nanoseconds. Required wait states through the bios setup for faster cpus to use same memory as slower CPUs. Includes: fast page mode (FPM), extended data out (EDO), and burst EDO (BEDO) DRAM.

Storage device standards

Legacy: IDE/EIDE (integrated electronics drives) (aka parallel ATA) and SCSI. Current: Serial ATA (SATA).

FE80::/10

Link local unicast range

LCD

Liquid Crystal Display. breakthrough that allowed displays to be smaller, more portable. Analog (requires modulation by the graphics adapter and demodulation by display device) or digital.

LRDIMM

Load reduced memory module. Maintains parallel communication between memory controller and register for performance improvement.

802.2

Logical Link Control (data link comms are managed. MAX sublayer watches out for data collisions and manages physical addressing)

CMOS battery

Long-life no rechargeable lithium ion

DDR2 SDRAM

Lower peak voltage than DDR (1.8v vs. 2.5v). Splits each clock pulse in 2, so it can perform 4 operations per clock cycle. 100mhz actual clock x 4 operations per cycle x 8 Bytes per operation = 3200 MBps. These modules are called PC2-3200

Monochrome display adapter

MDA. resolution: 720x350, mono color (text only)

Virtualization support

Many CPUs support virtualization in hardware. Eases burden that software-based virtualization imposes. AMD-V is is inclusive of amd's cpus. Intel VT segments market for CPUs. Also may have to enable virtualization in the bios.

USB ports

Many temporarily attached devolves feature usb connectivity.

MBR

Master boot record. Executed by bios after successful post. Calls associated os's boot loader and continues booting up.

Disable execute bit (NX bit)

Max bit. CPUs refuse to execute any code put in this specific memory location. Malicious buffer overflow attacks less likely to succeed.

BD RE

Means re-recordable. ( similar to RW)

Biometric device

Measures one or more physical trait of an organism

Single channel mem

Memory controllers manage access to memory in chunks of same size as the system's bus data width. (64-bit cpu=memory controllers can transmit 64 bits at time

Parity checking

Memory. Rudimentary error check with no error correction. Works on a byte- ninth but added at transmitting end, removed at receiving end. If rcvng end does not agree with parity set in single byte, parity error results. 4 schemes: even & odd (used in systems that compute parity) Mark, space (don't compute parity but expect fixed but value).

Interface

Method of connecting two dissimilar items together.

802.6

Metropolitan Area Network

MiniSD

Mobile phones. 21.5mm x 20mm

AMR riser card

Modem, microphone, line in line out.

CNR riser card

Modem/USB/Home PNA, Ethernet, microphone, line in line out.

M.2 form factor laptops

Modern form factor. Moving away from Mini PCIe to newer M.2, which is faster technology and uses 22mm wide, 66-pin card edge connector. originally developed under the name NGFF next gen form factor. Keyed so that only a specific type of card can fit into a certain slot. Keys given letter names to distinguish them from each other. A (Wi-Fi, Bluetooth, cell cards), B (SATA and PCIe x2 SSDs), E (Wi-Fi, Bluetooth, cell cards), M (PCIe x4 SSDs).

Pagefile.sys

Modern ms os, optimized space that can deliver info to ram faster than general storage pool of drive.

ATX power connector

Modern power connector for ATX motherboards. Provides the six voltages required through one 20-pin connector.

BIOS security

Monitors integrity of contact on motherboard; if tampered with, BIOS will log and notify. Also allows for supervisor and user passwords. Need supervisor pw before entering bios setup utility; user password before operating system is started. Works with TPM , boots system only after authenticating boot device.

Star topology

Most common. branches each network device off a central hub or switch, making it easy to add workstations. If workstation goes down, doesn't affect network. However, if central device goes down, single point of failure.

Memory- Laptops

Most common: SODIMM. much smaller than standard DIMMs, 67mm long (2.6") 32mm tall (1.25"). come in 32-bit (72-pin) and 64-bit (144-pin SDRAM, 200-pin DDR, 200-pin DDR2, and 204-pin DDR3) options. MicroDIMM

Power supplies and voltage

Most computers require power supplies in 250 - 500 watt range.

ADSL

Most popular in-home. asymmetric DSL- DL speed 8Mbps, UL speed 1Mbps. Most are full duplex. ADSL and voice comms can work at the same time bc they use different frequencies on the same wire. Voice traffic= 0-4kHz, upstream - 25.875-138kHz. downstream 138-1104kHz

Read/write heads

Mounted on mechanism that moves them in tandem across both surfaces of the platters in hard drive. Older drives used stepper motor , newer use voice coils for more precise data location. One head per writable surface (2 per platter).

FF00::/8

Multicast range

Dual rail architecture

Multiple 12v rails supplied to different components that require 12v. Eg, one rail for CPU, other rail for all other components. If loads are not balanced, can lead to overdrawing one rail which could lead to shut down.

MIDI

Musical instrument digital interface. Devices realistically fabricate the music instruments that they represent might produce; MIDI files smaller than files that contain digitized audio waveforms. 5-pin DIN connector that look like original AT keyboard connector.

SLI

NVIDIA's scalable link interface- allows two identical graphics adapters to be joined by hardware bridge to create one virtual graphics adapter.

ATX12V 2.0 and EPS12V (servers)

Needed to power PCIe slots, 24 pin connector. No 6 pin auxiliary connector

NAT

Network Address Translation. Runs on your router and handles the translation of private, nonroutable IP addresses into public addresses. Three ranges reserved for private nonroutable IP addreses. NAT router makes Internet request on behalf of privately addressed device.

NOSs

Network OSs. controls the communication with resources and the flow of data across the network. e.g. UNIX / Linus / Windows Server series (2012, 2008, etc.)

NIC

Network interface card. Expansion card that connects computer to a network so that it can communicate to other devices on same network. Translates data from internal parallel data stream to serial data stream that makes up the frame used on the network. Has a connector for type of expansion bus used (PCI, PCIe, etc.) as well as connector for the type of network (RJ45 for UTP, antenna for wireless, BNC for legacy coax). Also need drivers.

Land grid array

Newer technology. Pins on processor rather than on expensive motherboard. Uses avoid with L shaped arm to lock cpu in place

battery calibration

NiCd- allow a full discharge once a month or so. Li-ion- allow partial discharge.

Motion sensir

Nintendo Wii, ms Kinect, Leap Motion controller (PC)

Flash-based ssd

Nonvolatile. Less power than HDD.

Liquid nitrogen and helium cooling

Not practical; only useful in setting over clocking records!

CHS Hard drive geometry

Number of sectors each track contains (more is better) , number of read/ write heads in disk assembly, number of cylinders in the assembly. Cylinders/heads/sectors. Num of cylinders only refers to cylinders on one writable surface. Cylinders x heads = total tracks throughout disk assembly. X that by number of sectors per track = total tracks. /2 = number of on. (Each sector stores .5kb).

BIOS setup utilities

Offer diagnostic routines for the BIOS to analyze state and quality of components that it inspects during startup. Temperature, set warnings when threshold crossed, etc. use the BIOS to set the system clock higher than what the system is rated for. Undervolting- lowering the voltage of the cpu and ram which reduces power consumption.

Tape back up

Older form of backup. Use magnetic tape medium instead of disks for storage. Hold more data but are much slower. Used for batch archival storage, not interactive storage.

DNS

One function: resolve hostnames to IP addresses. computers require IP addresses to connect to websites. DNS servers have databases where host-ip resolution pairs are stored.

Drive activity light

One led for all internal drives , disadvantage is you can't tell which drive is active.

OSI model

Open systems Interconnection model. standards to keep communications clear. 1-7: physical, Data Link (media access control and logical link control), Network, Transport, Presentation, Application

Expansion slot

PCI, PCIe, PCI-x. Most visible part of motherboard. Usually 1-6 inches.

Beep code

POST can end with a beep code or displayed code to indicate the error encountered.

Hard disk

Permanent storage and quick access; reside inside computer. Use magnetic storage medium. 3 components: controller, hard disk, host bus adapter

Hard disk

Physical storage medium. Info stored on small disks /platters.

Raid 3/4

Place parity on single drive, varying results when drives fail.

USB flash drives

Plug n play. Removable drives. Small, lots of storage. Software interface allows for drag and drop file transfers.

power over Ethernet

PoE. useful when you need a wireless access point in a relatively remote location that does not have power outlets. The access point and the device it plugs into (switch) must support PoE,

Front panel connectors

Power button, power light, reset button, drive activity lights, audio jacks, usb ports

Cold swappable

Power needs to be off before inserting/removing to protect motherboard and also for it to be recognized

POST

Power on self test. Series of system checks performed by the system bios and high end components. Verifies integrity of bios itself, as well as analyzing and cataloging buses, boot devices, and verifying size of primary memory. Once post is completed successfully, bios selects boot device highest in configured order and executes master boot record

Output devices

Printers, speakers, display devices

Multicore architecture

Processor has separate processor dies in the same package.

PROM

Programmable ROM could be erased by ultraviolet light and reprogrammed. Flash memory is electronically erasable PROM (EEPROM).

Southbridge

Provides support to slower on board peripherals. PS/2, serial ports, serial and parallel ATA, etc. these resources do not need to keep up with the external clock of cpu and do not threaten to bottleneck system.

Keyboard

QWERTY. Numerical keys above alphabetic keys send scan codes to computer different from those in numerical keypad. IBM PC/AT keyboard had 84 keys, had to use numlock. 101 keys version. 104 key adds Windows specific buttons. keyboard . Each key completes an individual circuit when pressed, sending a scan code to the computer. Keyboard controlling chip interprets signals for computer. Dvorak simplified keyboard placed characters most commonly used closer to fingers.

Tape backup formats

Quarter inch cartridge (QIC) 200KB-1GB; digital linear tape (DLT) up to 800 GB; eight millimeter (data8) up to 60 GB; digital audio tape (DAT)/digital data storage (DDS) up to 300 GB, native; linear tape open (LTO) up to 2.5TB

Piezoelectric effect

Quartz crystal vibrating when exposed to current

QPI

Quick path interconnect. Replaces memory controller; moves from north bridge to cpu itself.

RJ-11

RJ 11 flat satin cables for telephone hookups, 2 pin

RJ series

RJ 11 flat satin cables for telephone hookups, RJ-45 larger and used in Ethernet networks that use twisted pair cabling. Ethernet interfaces are 8 pin connectors

RJ-45

RJ-45 larger and used in Ethernet networks that use twisted pair cabling. Ethernet interfaces are 8 pin connectors

RAID10

Raid 1+0. Adds fault tolerance to striping of 0 through mirroring of 1. Requires 4 drives, half for mirroring.

RAM

Random access memory- where currently used data and instructions for the cpu.

ROM

Read only memory. Boot. BIOS, and POST.

Undervolting

Reduce clock speed through bios and exponentially reduce heat.

Throttling cpu

Reducing op frequency of cpu during times of less demand or battery operation.

RAID

Redundant array of independent disks. Way of combining storage power of more than one hard disk for a purpose (increased performance or fault tolerance).

RDIMM

Registered memory modules. Include specialized chips that act as buffers for all signals except data signals. Memory controller communicates in series with register, instead of in parallel with memory chip. Register performs parallel communication with The chips.

Passive memory cooling

Relying on ambient case airflow to cool through enhanced heat dissipation- heat sinks or heat spreaders.

ATX12V 2.2

Replaced 6 pin connector with 150W 8 pin PCIe connector.

LGA 2011

Replacement for LGA 1366

ExpressCard (2.0)

Replaces PC Card (CardBus) technology for laptops. launched by pCMCIA (personal computer memory card int'l). a way to support USB 2.0, 3.0, and PCI Express connectivity for portable computers. Portable computers can be adapted to support faster versions of technologies that they might not natively support. (Gigabit Ethernet, IEEE 1394b (FireWire), eSATA, etc.) Expresscard 1.x: USB 2.0, 480Mbps; 1.x: PCIe 1.0 x1, 2.5 Gbps, 2.0: PCIe 2.0 x1 or USB 3.0, 5Gbps. ExpressCard/34 = 75mm in length, 34mm wide, 5mm thick.

DDR3 SDRAM

Roughly doubled DDR2. Peak voltage 1.5v. Most common found range of actual clock speeds tend to be 133MHZ to 300MHZ. 8 operations per cycle. 1600MHz motherboard (200MHz actual clock speed) = you need memory module with DDR3-1600 chips and module called PC3-12800, for total throughput of 12,800 MBps.

DisplayPort

Royalty-free digital display interface from Video Electronics Standards Association that requires less power than other digital and VGA. Functionality similar to HDMI and dvi, adapter automatically lowers voltages to those required by DisplayPort. 20-pin connector with keying at bottom right and two hooks to keep in place, released by push button

Flash memory

SD cards, other memory cards, usb flash drives. Name derived from easily being able to use electricity to alter the contents of memory instantly. Still used in devices that require non volatile way of storing data and code used in booting the device, like routers and switches

SD / memory cards

SD most popular removable memory card. Based on MMC (multimedia card) format. 32mm x 24mm. SD has write-protect notch. Additional cards include compactflash (CF) and xD-picture card.

Wear leveling.

SSD. spreads the write operations over device constantly.

SFTP

Secure File Transfer Protocol. used as an alternative to FTP- secure, encrypted connection.

SATA

Serial ATA. Orderly progression of data in a single-file path. (Superior to placing multiple bits in parallel and trying to synchronize their transmission). First: SATA 1.5Gbps- used 8b/10b encoding scheme that requires 2 non-data overhead bits for every 8 data bits. Result is 20% loss of bandwidth. Divide transfer rate by ten to determine throughput. SATA 3Gbps and SATA 6Gbps.

Bus architecture

Serial or parallel connectivity

Video card chipset fan

Set of chips mounted on adapter; cooling half of adapter has vents to exhaust hot air

Northbridge

Set of chips that performs one function: mgmt of hi speed peripheral comms. Comms with integrated video using PCIe and processor to memory comms.

32- /64- bit processors

Set of data lines between cpu and primary memory can be 32 or 64 bits wide. 32 or 64 bit internal registers. Also, registers may only be 32 bit, but with 64 bit bus where two separate pipelines receive info simultaneously.

DIMM for DDR3

Similar to DDR2- 240 pins and one keying notch in a different place.

Raid 6

Similar to raid 5, but can lose two disks and still function. Uses equivalent of 2 parity disks for redundancy as it stripes data.

SMT

Simultaneous multithreading

SCA

Single connector attachments - devices/nays with a single connector that contains both data and power. Ground leads longer than power leads so they make contact first and last. Drives built on SCA are hot swappable.

SDR SDRAM

Single data rate synchronous dynamic ram. The original SDRAM. Legacy. Every tick of the system clock = 1 bit of data per data pin. Therefore, 64-bit processor (8 bytes parallel data bus width) = 100?MHZ clock produces 800MBps of throughput. If you use dual-channel memory, the throughput would be doubled.

SIMM

Single inline memory module

SIMM

Single inline memory module. Legacy

SIPP

Single inline pin package. Legacy

PCIe link

Single lane or combined collection of lanes the switch interconnects between devices

Analog sound jacks

Six jacks capable of 8-channel audio (7.1 surround sound). 1 center, 2 right/left front/middle/rear, 1 subwoofer.

SODIMM

Small outline DIMM for notebooks, tablets, etc. including older 32-bit (72 and 100 pin config) and 64-bit (144-pin SDR SDRAM, 200-pin DDR/DDR2 and 204 DDR3) . All 64-bit modules have single keying notch. 144 pin slightly off center , 200 and 204 off center.

SODIMM

Small outline dual inline memory module.

LGA 1366

Socket B. Intel only

LGA 1155

Socket H2. Intel only. Sandy bridge/ ivy bridge

LGA 1150

Socket H3. Replacement for lga 1155 to support haswell and broadwell chipsets

LGA 1156

Socket h. Intel only.

LGA 775

Socket t. Intel only

SSD

Solid state drive. No moving parts. Limited to a finite number of write options. Wear leveling spreads the write operations over device constantly. Reads more quickly, less power, more reliable and less susceptible to damage. Less storage space than conventional: 2TB vs. 8TB Max

SSHD

Solid state hybrid drive. Conventional HDD with substantial amount of NAND-technology solid state storage. Known to the os as a single drive - user cannot access individual components.

Hybrid drive

Solid-state hybrid drive or dual-drive storage. Both can take advantage of solutions e.g. Intel's smart response technology which determines which data is most valuable and accessed most frequently and loads a copy to ssd. Does not make sense for systems that access data randomly.

Swap file /page file

Space on hard drive when you need to Use hard drive as add'l ram.

Liquid cooling

Special water block conducts heat away from the processor. Water is circulated the block, and then through the radiator (for cooling). Main benefit is silence. Only fan needed is on radiator to cool water.

IEEE 1394 standard

Speed and efficiency. Achieve rated rates through different encoding scheme. More power than USB, as well (1.5A X 30VDC= 45W power) . FW 400: 400 Mbps half-duplex. 1394b/ 800: 800 Mbps full duplex. 1.6Gbps, 3.2Gbps as well- still 1394b. 4.5 m Max cable. 63 device Max. 1394c- standardized running FireWire over category 5e infrastructure that supports Ethernet. Meant to network devices together and allow direct communication without going through central host. Can bridge as many as 63 devices together.

HDD speeds

Spin rate of platters : 5400 , 7200, 10,000, 12,000 rpm.

Scythe ninja series

Stack of thin aluminum fins with copper tubing running up through them. Passive cooling device; very effective.

Game pads and joysticks

Standardized connections have included DA15 game port or joystick port, RS-232 port, and USB port.

SRAM

Static random access memory. Uses bistable latching circuitry to store each bit. Bag g Used for cache memory. Doesn't require refresh signal like DRAM. Chips are more complex/expensive, but faster. DRAM access times: 40 ns or more; SRAM 10 ns or better.

Serial connectivity

Superior to parallel connectivity. Transmit and receive signals over single circuit. Allows faster speeds and more throughout. Limited only by capability of transceivers. Examples: SATA, USB, IEEE 1394/FireWire, PCIe

Virtual memory

Swapping. Cannot be used directly from hard drive; must be paged in as oldest contents of RAM are paged out to hard drive.

PCIe lane

Switched point to point signal path between components.

SMP

Symmetric multiprocessing. Two or more processors use the same resources.

SDRAM

Synchronous DRAM. Shares clock with system-bus clock. All local bus components use. Ties SDRAM with speed of FSB and thus processor.

Non-parity memory

Systems that do not reserve space for parity bit.

Host-to-Host layer (transport)

TCP/UDP

Rear exhaust fan

Takes hot air out of system

Process/Application Layer

Telnet, FTP, LPD, SNMP, TFTP, SMTP, NFS, HTTP, POP

Peltier cooling devices

Thermoelectric cooler. TEC. Transfers heat from one side of equipment made of one material, to other side of equipment, made of other material. Have hot side and cold side. Cold side should be against CPU. Hot side mated with heat sink. Condensation likely. Foam can remedy. Smartphones can be used as wireless gateway. Anytime you are in service area, you can use adapter to gain access to the Internet.

Thermal compound

To fill the gap between CPU and heat sink so as to avoid super heated pockets of air

Scanner

Today, ISB, network, or wireless attachment of some form popular. TWAIN- -generic term for class of drivers associated with scanners. Scanners use light to reflect off of a surface and measure reflections of different dots that make up the grid. More DPI better resolution. Charge Couple Devices CCDs are common today- they convert light they receive into electrical impulses, which is forwarded to software for processing.

802.5

Token Ring LAN (access packet called token circles the network. If you have the token, you can send data; otherwise wait your turn.)

TOSLINK

Toshiba's interface is digital fiber-optic audio technology implemented with its own connector.

TCP

Transmission Control Protocol. Layer 4/ Host-to-Host Layer. Guarantees delivery. 3 way handshake, acknowledgements. Connection oriented.

TPM

Trusted platform module. Dedicated security coprocessor. BitLocker uses TPM to encrypt entire drive. Including operating system files, registery, hibernation file, etc.

Fan power connectors

Two main types: 4 connectors = +5VDC (volts direct current). 3 pin chassis-fan connector is more rare, calls for +12VDC for heavier duty fan. 4 pin fan offers tachometer on pin 3 so bios can measure fan speed. Pin 1 and 2 ground and power. Pin 4 "CPU FAN PWM" pulse width modulation- used to send a signal to fan to control its speed.

Chipset

Two major groups: north bridge and south bridge. Collection of chips or circuits that perform interface and peripheral functions for processor . Dictates how motherboard communicates with installed peripherals.

USB standard

Two types of connectors: type A and type B. Standard USB cable has some type A connector on one end (faces system) and one type B connector on the other end (faces peripheral). Max USB cable length: 1.x- 3m ; 2.0- 5m ; 3.0- 3m. 7-bit identifier = 2^7 possible addresses = 127 devices (last address broadcast)

USB 2 vs. 3

USB 3 requires shielding to withstand EMI; has 5 additional pins; supports bursting and continuous streaming; dual simplex that imitates full duplex ( as opposed to half-duplex); data is transmitted at will ( doesn't wait for host); 3.0 end points can control power Mgmt (don't rely on host); power- 2.0 : 100mA-500mA; 3.0 : 150mA-900mA. ;

Ultra XGA

UXGA, 1600x1200

UEFI

Unified extensible firmware interface. Successor to BIOS. Extensible feature allows access to system resources for storage of add'l modules that can be added and allow for things like secure boot.

UPS

Uninterruptible power supply.

Wireless NICs

Unique characteristic of requiring connecting device to be configured before configuring NIC. (Wireless access card or ad hoc partner computer).

FC00::/7

Unique local unicast address range.

Watt

Unit of power, and the unit used to rate power supplies.

Simple Service Discovery Protocol

Universal Plug and Play. allows devices to connect to the network and discover each other automatically.

UPnP

Universal Plug n Play. standard designed to simplify the process of connecting devices to a network and enable those devices to automatically announce their presence to other devices on the network. Client needs to be a DHCP client and the service uses UDP port 1900. No authentication mechanism, any device or user is trusted and can join the network. Configure router to not allow UPnP connections from external connection.

USB port

Universal Serial Bus. Used for connecting multiple peripherals through one port. USB 1.x - 12Mbps(1.5MBps) , 2.x - 480 Mbps (60 MBps), 3.0 - super speed (5 add'l pins) 5Gbps.

UDIMM

Unregistered DIMM (unbuffered). Usually, the term ECC memory means UDIMM

Bus

Used in any parallel or bit-serial wiring implementation where multiple devices can be attached at the same time in parallel. E.g. scsi, usb, ethernet. Rated by bus speeds.

RCA jack

Used to transmit audio and video. Yellow coded rCA connector on a PC video card- typically for composite video output. Can be deployed with a S/PDIF connector (for digital audio). Considered coaxial.

UDP

User Datagram Protocol. Connectionless, faster.

USB-to-Ethernet adapter

Uses existing USB port to gain access to energy needed to power the circuitry in adapters Ethernet interface. USB port also communication pathway for data across Ethernet network. Another device uses Ethernet network to extend range of USB ports and devices.

Mouse

Uses some form of motion detecting mechanism and translates to onscreen cursor motion.

Digitizer

Uses stylus to trace analog art/media and turn it into a digital representation.

BD-ROM

Uses violet laser, instead of red laser used by other optical drives. Shorter wavelength (405nm) . Laser can be focused on smaller area of disc. Possible to add more than two layers. 25GB single layer. 50 GB dual layer. Double side double layer 100GB.

Adapter configuration

Usually plug and play aka resources handed out automatically without jumper settings or device drivers installed automatically. Some modern adapters like two or more PCIe graphics adapters require special hardware / adapters that requires configuration through OS for advanced features.

display port- laptops

VESA video electronics standards association introduced DisplayPort in 2008 intended to replace VGA and DVI, to be for video devices only but can transmit audio and video simultaneously.

Lapping the heat sink

Very fine sanding element to smooth the mating surface and improve cooling.

Audio/Video editing workstations

Video Enhancements, Specialized audio, Specialized hard drives. Assumes the use of nonlinear editing (NLE) schemes for video= stores the video on the local drive instead of editing being performed in real time as the source video is fet into the computer. NLE requires much more RAM and disk space. Benefit from graphics adapters with multiple video interfaces that can be used simultaneously. Dual monitors is a must. Graphics adapters that support API's (application programming interfaces) like CUDA (NVIDIA's compute unified device architecture, parallel computing architecture for breaking down larger processing tasks into smaller tasks for simultaneous GPU processing) and OpenCL (open computing language is a similar, cross-platform, open standard). Specialized audio - 6-8 digital audio channels instead of 2 analog(standard). MIDI port. Uncouple the hard drive that contains the OS and applications from the one that houses media files, which greatly reduces the need for multitasking by a single drive. SATA 6Gbps drives that spin at 7,200rpm and faster recommended. SSD can be considered because they're fast, but not very large. If you use external drives, ensure to use an eSATA connection or thunderbolt or USB 3.1 for speeds. RAID 0, disk striping without parity. improves read and write speeds. RAID 5, fast read write speeds plus redundancy to protect against data loss.

VGA

Video Graphics Array. resolutions: 640x480 (16 colors), 320x200 (256 colors)

PCI-x expansion slot

Visually Indistinguishable from 64 bit pci. Version 1- 66 MHz (533MBps) or 133 mhz(1066 MBps)... Version 2- 533MHz with 8byte bus = 4266 MBps (4.3GB) Shared bus topology. Each slot shares 22pins in common regardless of link width

SSD categories

Volatile DRAM-based and nonvolatile flash based.

802.11a

WLAN bandwidth of up to 54Mbps in the 5GHz frequency spectrum. uses OFDM (more efficient than FHSS or DSSS). never very popular (802.11b was cheaper)

Reset button

Way to reboot computer from cold startup w/o removing power from components. Prolongs life of electronics affected by power cycling. Gets around software lockups. Disadvantage: certain circuits need time to drain their charge.

Secure boot

When a Certain level of UEFI is used, system firmware can check digital signatures to ensure boot files have not been tampered with. Files include: option ROMs, boot loader, other OS boot files.

Shared bus topology

When you mix 33mhz and 66mhz adapters it will slow all adapters to 33mhz, for example.

Home Server PCs

When you want many of the features of a server but don't want to mess with server OS (windows server / linux). Essentially powerful client systems with a standard non-server OS. differ from enterprise servers to the point that they qualify as custom configs. Enhancements: media streaming capabilities (homegroups- work with libraries, can be shared among devices in homegroup), file sharing services, print sharing services, Gigabit NIC, RAID array. File and print sharing services. Clients in home server network can upload/download files to /from server. Home server should be attached to a wired switched port in an ethernet switch or wireless access point. the NIC and switch port should be capable of gigabit speeds to ensure no bottlenecks. running client NICs at gigabit speeds should be avoided so server isn't saturated. RAID array to protect from accidental loss.

Platters

Where actual data is stored by the read/write heads.

802.11

Wireless Networks

PCIe link widths

X1 x2 x4 x8 x12 x16 x32 (1,4,16 most popular). Physical size related to width.

Hot swappable

You can insert/remove with the system powered on.

ZIF socket

Zero insertion force socket (Pga array). Plastic or metal lever locks cpu in place.

protocol

a common language for communication; set of rules.

privacy filter

a panel that fits over the front of a display and uses a polarization effect to intentionally limit the viewing angle of the monitor.

UTP cat 3

able to transmit data at speeds up to 10Mbps. 10BaseT installations before cat-5

ACL

access control list. set of rules that determines which traffic gets through the firewall and which traffic is blocked. typically configured to block traffic by IP address, port number, domain name, or some combo.

5 steps to setup secure wireless router

according to Wi-Fi Alliance. 1. change SSID, 2. change admin username and pw, 3. select AES or WPA2, 4. choose good security passphrase, 5. from the clients, select WPA2 and enter the security passphrase to connect.

AMOLED/PMOLED

active/passive matrix oled. AM requires more electrodes (a pair for each OLED). PM displays limited by things such as the need to group the electrodes for the OLEDs.

piconet

ad hoc network ; no central communication point required. dynamically created. Bluetooth enabled device can communicate with up to seven other devices in one piconet.

ARP

address resolution protocol. Resolves logical IP addresses to physical MAC addresses built into network cards.

bluetooth 1.2

adopted 2003; 1Mbps

centralized processing

all programs run on the same computer

distributed processing

allows computer to access programs across other computers. (first example: minicomputer). User's computer: front end, for data entry. program stored on back end.

Class B

always have first two bits set at 10 (decimal values from 128-191). Network portion: 16 bits, 16 bits for host ID. 2^14 networks (16,384) each with as many as 65,534 (2^16 - 2).

resource

any item that can be used on a network. printers and otehr peripherals, disk storage and file access, applications, etc.

thin clients

any machine that divests itself of all or most local storage and varying levels of ram and processing power without necessarily giving up all ability to process instructions and data. Possess a true network connection and the intelligence to locate the server before turning over processing control. turning over processing and storage capabilities to server can create single point of failure. thin clients have no offline capability. Thin client OSs: Thinstation, Windows Embedded Standard (WES7), Lenovo Terminal Operating System (LeTOS). Flash-based storage/small form factor RAM.

access point

any point that allows a user on to a network. commonly used in reference to wireless access point, connect to network via 802.11 technology.

radius server

authentication server. needed for enterprise security wireless setting.

APIPA

automatic private IP addressing. Used when unable to locate a DHCP server on Windows OS. computers will be able to communicate on the local network, not remotely.

pixel addressing

avitve-matrix and passive-matrix. dual scan is a passive-matrix variant. main differences: quality of image. each type uses backlighting (lighting behind lcd panel) to make screen easier to view. modern LCD panels use LEDs.

802.11g

bandwidths of 54Mbps in the 2.4GHz frequency spectrum using OFDM or DSSS. backwards compatible with 802.11b. still popular today. However, if there are 802.11b devices on an access point, access point reverts back to DSSS modulation and therefore 11Mbps.

BRI ISDN line

basic rate interface. typically, two B channels and one D channel. one B channel used for voice call whilt the other is used for data transmissions.

printer paper

basis weight- weight of a ream(500 sheets). caliper- thickness of paper

network ID

beginning part of the IP address (network portion). Does not have to be a specific fixed length. all hosts addresses on a network must be unique, but will have same network ID.

client-server resource model

better for large networks (more than 10 comps). more secure, easier to administer with centralized control.

smart cameras

built-in wireless network connectivity for easy picture and video transfers.

network topologies

bus, star, ring, mesh, hybrid

ShareNet

by Novell. first LAN.

CSMA/CA

carrier sense multiple access/collision avoidance. wireless networks use this (as opposed to ethernet, CSMA/collision detection). collisions generally avoided, when they do happen, sender must wait random period (back-off time).

Mobile Hotspots

cell phone providers offer network cards that allow your laptop computer or other device to connect to the internet from anywhere you can get a cell signal. MiFi. MiFi card allows you to connect up to eight Wi-Fi-enabled devices as a MiFi cloud to get Internet access.

servers

centralize the control of resources and security, reducing administrative difficulties. can perform several different roles, eg providing files to the users on network (file servers) or hosting printing services (print servers). Can be multi-purpose or single-purpose. dedicated (Assigned to provide specific applications/services and nothing else. fewer resources, more efficiency) nondedicated servers (assigned to provide one or more network services and local access. Expected to be more flexible, can act as a workstation as well as a server.

802.11n

claims to support 600Mbps, typical throughput is 200Mbps to 450Mbps. works in both 2.4GHz and 5GHz. Enhancements include: 40MHz channels (combines 2 channels to double throughput), multiple-input multiple-output (MIMO) multiple antennas (4 streams, 8 antennas) rather than a single antenna, and channel bonding. backwards compatible with 802.11a/b/g.

CIDR

classless interdomain routing. allows you to use other than default subnet masks. /8 through /15 notations can only be used with Class A network addresses; /16 through /23 Class A and B; /24 through /30 Class A, B, and C.

coaxial cable

coax. contains a center conductor core made of copper, surrounded by a plastic jacket with braided shield over it, and either teflon or plastic (PVC) coating covers this metal shield. The thicker the copper, the farther a signal can travel, the higher the cost and less-flexible.

CDMA

code division multiple access. 2nd most popular cell standard. 3G. Sprint and Verizon. Won't work outside the US.

TCP/IP protocol suite

collection of different protocols that work together to deliver connectivity.

Inverse Multiplexing or Bonding

combining B channels to maximize data throughput.

full duplex communication

computer can send and receive data simultaneously.

peer-to-peer resource model

computers act as both service providers and service requestors. Also referred to as workgroups. Makes administration difficult.

workstations

computers on which the network users do their work. Basically everyday computers. Also known as client computers.

Gaming PCs/workstations

computers optimized for running modern games (high end multiplayer games). Enhancements: CPU enhancements, video enhancements, specialized audio, enhanced cooling. CPU must generate action, graphics subsystem must keep up with action. Sometimes overclock (change BIOS clock frequency settings). CPU life won't be as long. Enhanced cooling necessary. high end graphics adapters come equipped with cooling mechanisms. video enhancements: NVIDIA's SLI and ATI's Crossfire technologies. Video cards requrie their own graphics processing unit (to process its code). These GPUs require their own RAM (4GB+). CUDA- /OpenCL capable GPUs. S/PDIF and HDMI high quality HD digital audio.

Portable projector

condensed video display units with a lighting system that projects the VDU's image onto a screen/flat surface. focusing mechanism included on the lens to adjust for variable distances.

DHCP server

configured to provide IP configuration information to clients automatically (lease). lease typically includes: IP addr, subnet mask, default gateway, DNS server addr.

modem

connect to a network or internet using plain old phone lines. modulate and demodulate digital signals that computers use into analog signals that can be passed over telephone lines. fastest modems transferred data at 56Kbps.

printer controller circuitry - laser

converts signals from the computer into signals for the various assemblies in the laser printer using a process known as rasterizing.

Clock frequency

crystal (xtl) or system clock keeps the time for the flow of data on the motherboard

DCPS - laser

dc power supply. High voltage pover supply can't power the other components in the printer. logic circuitry and motors require low voltages, between 5VDC and 24VDC. the DC power supply converts house current into three voltages: 5VDC and -5VDC for the logic circuitry and +24VDC for the paper transport motors.

bluetooth v4.2

dec 2014; max data rates of 24Mbps. uses available 802.11 signals as a transmission medium, otherwise max speed is 3Mbps.

resolution

defined by how many software picture elements (pixels) are used to draw the screen. higher resolutions = more info can be displayed in the same screen area, however may appear smaller and be harder to see. resolution is described in terms of the visible image's dimensions, which indicate how many rows and columns of pixels are used to draw the screen. (1024x768 = 1024 across, 768 down). memory requirement increases as color depth increases. 24-bit color depth = can display each pixel in one of 2>24 distinct colors. 24-bit graphics means that each pixel requires 24 bits of memory to store that one screen element. 786,432 pixels = 18,874,368 bits or 2.25MB.

tablets

defining characteristic: touchscreen. resistive and capacitive.

IEEE 802.15.1

describes wireless personal area network based on bluetooth 1.1

docking station

designed to stay behind when laptop is removes; extension of the motherboard of a laptop and contains things like a full-sized drive bay and expansion bus slots. port replicator.

Thunderbolt - laptops

developed as an offshoot of the display port technology. Apple announced a mini DisplayPort standard in late 2008, added support for PCIe, renamed it Thunderbolt. Video devices, hard drives, printers, laptop docking stations, PCIe expansion enclosures- it has a lot of functionality and supports several types of peripherals (notjust video devices). Thunderbolt 1 = 10Gbps, 2: 20Gbps, 3: 40Gbps.

digitizer

device that can be written or drawn on, and the content will be converted from analog to digital images.

hubs

device that links several computers together. simple/not intelligent. repeat any signal comes in and broadcasts it to all other devices listening on ports. work at layer 1 of the OSI model. passive hubs connect all ports together electrically but do not have their own power source. Active hubs use electronics to amplify and clean up signal before broadcasting.

RAS server

dial up server. remote access server.

DLP

digital light processing. Popular technology for rear-projection TVs and some portable projectors, as well. DLP chips, or optical semiconductors, have roughtly as many rotatable mirrors on their surface as pixels in the display resolution. light source and colored filter wheel are used to switch among primary and secondary colors in synchronization.

DSL

digital subscriber line acess. utilizes existing pone lines and provides fairly reliable high-speed access. need DSL modem and network card in your computer. Ethernet cable with an RJ-45 connector to plug network card into DSL modem and phone cord to plug the DSL modem into the phone outlet. One plus is that you do not share bandwidth with other customers.

DSSS

direct=sequence spread spectrum used for data encoding (802.11). Adds the data that is to be transmitted to a higher-speed transmission. the higher-speed transmission contains redundant information to ensure data accuracy. packets can be reconstructed in event of disruption.

ribbon cartridge

dot-matrix printers. cloth or polyester ribbon soaked in ink and coiled up inside a plastic case. Once ribbon has run out, discard and replace.

fiber-optic connector type

dozens; three of the most common are ST, SC, and LC.

multiple displays

dual view - microsoft's multimonitor feature. WDDM windows display driver model requires that the same driver must be used for all graphics adapters.

DFS

dynamic frequency selection. because military, weather, and and commercial radar operates in 5GHz range, need to avoid conflicts. DFS detects radar interference and dynamically adjust to a different frequency range.

DNAT

dynamic network address translation. translates a group of private addresses to a pool of routable addresses. This is used to make a resource that's on a private network available for consumption on public networks by appearing to give it a publicly available address. eg if a web server were beind a nat enable router and didn't have it's own public address, it would be inaccessable to the internet.

MAC address

each NIC on same network must have different hardware addresses.

Ring topology

each computer connects to two other computers, joining them in a circle/unidirectional path. difficult to add new computers. If one entity is removed, whole network goes down.

toner

each model of laser printer uses a specific toner. Check the printer's manual.

control, interface, and power circuitry -inkjet

electronic circuitry for printer control, printer interfaces, and printer power. Printer control circuits are usually on a small circuit board that contains all of the circuitry to run the stepper motros. also responsible for monitoring the health of the printer and for reporting that information back to the pc. Interface circuitry (commonly called a port) makes the physical connection to whatever signal is coming from the computer. also connects the physical interface to the control circuitry. power circuits convert 110v or 220v from a wall outlet into the voltages that the inkjet printer uses, usually 12v and 5v.

EGA

enhanced graphics adapter. resolution: 640x350, 16 colors

patch panel

essentially a large hub that is rack mounted. it houses multiple cable connections but possesses no network intelligence. sole purpose to connect cables together. short patch cables are used to plug into the front-panel connectors, and longer, more permanent cables on the back side.

super VGA

established by the Video Electronics Standards Association (VESA) in response to IBM's monopoly on the video standards. SVGA could support 16 colors at a resolution of 800x600 (VESA standard). Expanded to 256 colors at 1024x768 pixels.

UTP cat 7

every wire pair is shielded, which provides better resistance to crosstalk and external noise. handles 10Gbps at up to 100 meters. also known as class F cabling.

XGA

extended graphics array. IBM introduced in 1990 and available only as a Micro Channel Architecture (MCA) expansion board (versus ISA or EISA, for instance). XGA could support 256 colors at 1024x768 pixels, or 65,536 colors at 800x600 pixels. optimized for GUIs of the day, such as Windows and OS/2. interlaced technology when operating at 1024x768 resolution, meaning that it scanned every other line on each pass using persistence of vision phenomenon instead of scanning every line one at a time on each pass. 1080i refers to interlaced, versus 1080p progressive scanning.

MicroDIMM laptops

extremely small RAM form factor (over 50% smaller than SODIMM). 45.5mm (1.75") long and 30mm (1.2") wide. No notches in the bottom. /More square shaped than SODIMM. 64-bit modules with 172 or 214 pins for DDR2.

Installing/configuring NICs

fairly easy to install; type of expansion card.

fault tolerance vs. redundancy

fault tolerance seeks to maintain access during failure, while redundancy ensures recoverability after the failure.

fiber optic internet

fiber optic cable used mostly for telecommunications and network backbones. Much more expensive than copper to install and operate.

FTTH

fiber to the home. cables are 100-percent fiber from data centers to home. 75Mbps / 150Mbps.

FTTN

fiber to the node, or curb. fiber to the phone company's utility box near the street and then copper from there to house. 25Mbps max speed.

ST connector

fiber-optic. Straight tip. developed by AT&T. BNC (bayonet neill conc...) attachment mechanism that makes connections and disconnections fairly easy.

SC connector

fiber-optic. Subscriber connector. also known as square connector. latched, making it impossible to pull out without releasing its latch.

class C

first 3 bits: 110. (192-223) designed for smaller networks. 24 bits for network. 2^21 (2,097,152 networks. only 254 hosts per network.

class A IP address

first bit set as 0. designed for very large networks. default network portion for class A networks is the first 8 bits, 24 bits left for host identification. 8 bits = only 126 class A network addresses available. 16,777,214 hosts.

802.11ac

first commercial wireless standard that claims to offer the speed of Gigabit Ethernet. OFDM modulation and 5GHz range. furthers 802.11n channel bonding and MIMO. can bond up to eight for a 160MHz bandwidth. 333 percent speed increase. doubles MIMO capabilities of 802.11n to eight streams (16 antennas). theoretical max speed is 6,900Mbps but most current devices can get 1,300Mbps. common throughput is under 1Gb. Beamforming (sending signal in direction of client instead of transmitting omnidirectionally).

RJ connectors

for Twisted pair cabling. Registered Jack. crimper used to attach connectors.

RJ 45

for UTP cable. Room for four pairs.

FHSS

frequency hopping spread spectrum used for data encoding (802.11). hops transmission over a range of predefined frequencies. hopping is synchronized between both ends and appears to be a single transmission channel to both ends.

Fast Ethernet NIC speed

full duplex mode: 200 Mbps, half-duplex mode (100Mbps.)

Wi-Fi Antenna - laptops

generally built in, run through the top of the clamshell case to get the antenna higher up and improve signal reception.

Transfer Corona Assembly

given a high voltage charge, which is transferred to the paper, which in turn pulls the toner from the photosensitive drum. Static charge eliminator strip drains away the charge imparted to the paper by the corona. This allows the paper to un-stick from the EP cartridge. Two types- contain a transfer corona wire, or a transfer corona roller. transfer corona wire/roller both charged, but roller is in direct contact with paper and therefore supports higher speeds.

GPS

global positioning system. satellite based navigation system. three components: satellite constellation (US gov manages 32 GPS satellites, 24 are active, the rest backups. 4 satellites required for location and elevation, three for location), ground control network (monitors satellite health and signal integrity), and receiver. SPS standard positioning service (100m horizontally, 156m vertically), precise positioning service pps (22m horizontally 27.7m vertically)

GSM

global system for mobile communications. most popular cell standard. 3G. introduced first, now caught up to CDMA speeds. AT&T and T-mobile.

fuser

halogen heating lamp, teflon coated aluminum fusing roller, rubberized pressure roller. Halogen lamp heats the fusing roller to between 329 degrees and 392 degrees. the pressure roller pushes the paper against the fusing roller, which melts the toner into the paper.

storage- laptops

hard drives and optical drives. don't havr room for full-sized 3.5' hard drive. Use 2.5" or 1.8" form factor that is less than 1/2" thick. SSD - have same PATA/SATA and power connectors, usually specialized connector and single cable that handles data and power. ( no moving parts, faster, less heat, more expensive and less storage than HDD>) Hybrid Hard Drive: moving platters with some high-speed flash memory for frequently used files.

firewall

hardware or software solution that serves as your networks security guard. most important device on networks that are connected to the internet. filter packets based on rules set by network administrator. Most firewalls are configured as default deny.

HDSL

high bit rate dsl - DL speed 42Mbps, UL speed 8Mbps

routers

highly intelligent, network layer (3) use IP addresses to route traffic. can route packets across multiple networks and use routing tables to store network addresses to determine best destination. connect multiple networks to each other. do not forward broadcasts. connect one LAN to another.

Frame Rate

how many unique screens of content were recorded per second. Content recorded at 30fps and played back at 60Hz will look fine (2 copies of each frame displayed). if content shot at 24fps (most popular), would play back poorly. measure of unique content per screens of info displayed per second.

projection - brightness

how to keep ambient light from interfering with image's projection? increase brightness, measured in lumens. train the projector on larger area, reduces the lux. vice versa. projection systems are rated and chosen for purchase based on lumens of brightness. with no ambient light: home 1300lm office 2500lm, partial ambient light: 1500-3500lm, office 5000-6000lm. projector bulbs very expensive.

WPA2

huge improvement over WEP and WPA. uses counter mode CBC-MAC protocol (CCMP), which is based on AES (advanced encryption standard) security algorithm.

default gateway

identifies the IP address of the device that will allow the host to connect outside of the local network. (router). Required if you want to communicate outside your local net.

submarining

if you move the mouse pointer rapidly on a passive-matrix display, the mouse disappears altogether.

ISDN

integrated services digital network. digital, point to point network capable of max transmission speeds of 2Mbps, 128Kbps more common. Uses the same two-pair UTP wiring as POTS but can transmit data faster. unlike POTS, copper wire carried digital signals. need ISDN terminal adapter (connects to computer). also known as ISDN modem. not an actual modem because it does not convert digital signal to analog signal; ISDN signals are digital. Each channel can transmit data or voice. easy support for video teleconferencing.

plastics/frames

interchangeable with laptop case. Not all cases are plastic.

cable modem

internet access through cable service. plug network card into cable modem through ethernet cable, use cable tv jack instead of phone jack. Data over cable service internet specification (DOCSIS). Cable speeds not guaranteed, and can vary bc you are sharing available bandwidth within your distro network. Usually between 100 and 2,000 customers.

subnet mask ranges

know these. class A: 10.0.0.0-10.255.255.255 (255.0.0.0) 16.7 million ; class B: 172.16.0.0-172.31.255.255 (255.240.0.0) 1 million ; Class C: 192.168.0.0-192.168.255.255 (255.255.0.0) 65,536.

RJ 11

landlines. Room for two pairs.

USB ports- laptops

laptops use USB ports for expansion. majority of peripherals for laptops are USB expansion devices. Dongles allow conversion from USB to HDMI, Optical, bluetooth, Wi-Fi, smart card readers, etc.

daughterboard

laptops. to save space, components of the video circuitry are placed on a thin circuit board that connects directly to the motherboard. riser card.

laser scanning assembly- laser

laser scanning assembly shines on particular areas of the photosensitive, causing it to discharge in the area that has been exposed.

switches

layer 2 (like bridges), and they provide centralized connectivity just like hubs. hubs pass along all traffic, but switches examine the layer 2 header of teh incoming packet and forward it properly to the right port and only that port. downside- forward broadcast traffic.

file locking

legacy problem of first LANs. first software programs were not capable of being used by more than one user at a time.

RG-58U

less popular coax.

inkjet cartridge

liquid ink reservoir. the ink in these cartridges is sealed inside. once the ink runs out, the cartridge must be removed and discarded. Because the ink cartridge contains the printing mechanism as well as ink, it's like getting a new printer every time you replace the ink cartridge.

LAN

local area network. First one was ShareNet by Novell.

LC connector

local connector. developed by lucent technologies. MFF (mini-form factor) popular for use with fibre-channel adapters, fast storage area networks, and gigabit ethernet adapters.

LTE

long term evolution. used by mobile providers, dominating the 4G standards.

::1

loopback address equivalent of 127.0.0.1 in 4.

UTP cat 2

lowest grade cable that can have 4 pair of wires. 4Mbps.

Active Matrix (pixel addressing)

made up of several independent LCD pixels. Transistor at each pixel location is switched among various levels to activate opposing electrodes that aligh pixel's crystals and alter the passage of light to produce a particular shade. crisp, clean, does not require constant refreshing bc transistors conduct current in only one direction. requires more power bc there is one transistor for each red, green, and blue subpixel. Even with backlight off, screen can consume battery power.

static IP addressing

manually enter IP configuration information for each host. routers, servers, printers, and some workstations need to have static IP addresses. computers need to access these devices consistently.

WiMax

marketing name given to the IEEE 802.16 standard for wireless MAN technology.

bluetooth classes 1, 2, 3

max dist: 100m, 10m, 1m; power usage 100mW, 2.5mW, 1mW. uses the unlicensed 2.4Gz range for comms. signal hops to avoid interference.

printer upgrades

memory, network cards, and firmware. NIC: similar to the nic in a computer, but has a small processor on it to perform the management of the nic interface (functions that the software on a host computer would do). The NIC in the printer is proprietary. Firmware usually done from the machine hosting the printer (usually called the print server). Hard Drives- install multiple fonts to the onboard memory of the printer to speed up print jobs.

vampire tap

metal tooth sinks into cable (thicknet) and connects to the inner conductor. tap is connected to a DIX or DB15 connector.

hybrid topology

mix of other topologies.

mesh topology

most complex in terms of physical desigh. Each device connected to every other device. Rarely found in LANs bc of complexity of cabling. with x computers, (x x (x-1)) / 2 to figure out how many cables required. Expensive to install and maintain. high fault tolerance. Often used to connect multiple sites across WAN links. routers search multiple routes to find best path.

display systems

most display systems work the same way: comp sends a signal to the video adapter (expansion board installed in an expansion bus slot) telling it to display a graphic or character. (converts the single instruction into several instructions that tell the display device how to draw the graphic

rear projection

most implement LCD gates that shine a bright light through three LCD panels that adjust pixels in the same manner as an LCD monitor, except the image is formed by synchronizing the combo and projection of red green and blue images onto the same surface.

beamforming

most important innovation of 802.11ac. sends signal in direction of client instead of omnidirectionally transmitting.

smartphone

most popular computer device in the world. any mobile phone with its own processor and operating system.

twisted pair cabling

most popular today because of flexibility and low cost. consists of several (2 or 4 pairs) pairs of wire twisted around each other within an insulated jacket (PVC or plenum coating). STP and UTP.

Most Recent video standards

most recent video standards are probably extensions of SVGA or XGA. easy to predict the resolution based on name. When preceded by W, assume same vertical resolution but a wider horizontal resolution to accomodate 16:10 widescreen monitor formats. Q = horizontal and vertical esolutions were each doubled, making a final number 4 times the original. H - multiply by 16 for resolution.

host ID

must be unique to all hosts on network. All 0's means 'this network' all 1's means broadcast address.

nfc

near field communication. wireless technology that has become more popular. Most modern smartphones and tablest have NFC. uses radio frequency signals, can operate in three modes: nfc card emulation mode, which lets the device act as a smart card (useful for making payments). NFC reader/writer mode, alows the device to read information stored in an NFC tag on a label or poster. NFC peer-to-peer mode, which allows for ad hoc data transfer between two NFC enabled devices. slower data rates: 106Kbps, 212Kbps, 424Kbps. transmits at 13.56MHz. neither the miller coding or manchester coding schemes are encrypted, so it is possible to use man in the middle or relay attacks. potential hacker would need to be within a few meters to attempt it.

Mini PCIe - laptops

nearly all laptops built today use mini pcie slots for expansion cards. reside inside the case of the laptop and are connected via a 52-pin edge connector. come in two sized: full size: similar to ExpressCard devices measuring 30mm wide and 51mm long: Half-size cards 30mm wide and 27mm long. Like ExpressCard 2.0, Mini PCIe cards support USB 2.0 and 3.0 and PCIex1 functionality. 1.5 or 3.3V power options.

DoD model (TCP/IP)

network access (physical / data link); Internet (Network); Host-to-Host (Transport); Process/Application (Application, presentation, session)

NAT

network address translation. translates private IP addresses on your internal network to a public IP address on the internet. if you have multiple clients accessing the internet but only one external public IP address- NAT.

NIC

network interface card. Special expansion card that allows PC to communicate on a network. Must connect it to a cabling system that connects to other computers unless your NIC supports wireless networking. must install client software (comes with all OSs today), which allows the computer to communicate to the servers and request resources from them.

Wi-Fi

nickname referring to IEEE 802.11 standards.

Dial-up POTS

not used much, limitations on modem speed (tops out at 56Kbps). Dial up modems operate over regular phone lines. Plain Old Telephone Service.

laptop motherboards

often proprietary- designed to fit into small case. lack of standards, unlike with desktop motherboards.

daisy-wheel printers

oldest printing technologies in use. impact printer. uses a wheel (looks like a daisy) with raised letters and symbols on each "petal". when the printer needs to print a character it sends a signal to the mechanism that contains the wheel, called the print head. rotates the wheel until character in place, electromechanical hammer called a solenoid strikes the back of the petal containing the character, pushes up against the inked ribbon that strikes the paper, making the impression. Speed measured in characters per second. (2-4). advantages: can print on multipart forms as long as they can be fed into the printer properly. relatively inexpensive. print quality readable. LQ letter quality.

Bluetooth WPAN

one defining feature is that it is temporary by nature. Formed on an ad hoc basis. no central communication point is required. piconet.

RG-8

one of most common back in the day. thicknet. max segment distance of 500 meters and was used primarily for network backbones. Impedance of 50 ohms. 10Base5 ethernet. highly inflexible, needed vampire tap connector.

RG-58A/U

one of most common back in the day. thinnet. more often used in conventional physical bus. thinnet segment could span 185 meters, impedance of 50 ohms, 10Base2.

baseband vs broadband

one signal at a time per cable vs. multiple signals at the same time on one cable.

anycast address IPv6

one that has been assigned to multiple nodes (packet addressed to an anycast address will be delivered to the closest node).

multicast address IPv6

one used by multiple hosts to communicate to groups of computers. (IPv6 does not employ broadcast addresses).

Home Theater PCs

one workstation to control all components of home theater system. may store large amounts of data, stream to an output device, stream from internet, act as A/V tuner/receiver, mate input sources with output devices. Enhancements: video enhancements, specialized audio, special chassis, tv tuner requirements. HDMI is logical choice for connectivity (established standard, highest quality audio, video resolution, and video refresh rates.) Graphics adapters should have HDMI interfaces. HDMI capable of eight-channel 7.1 surround. at least, 7.1 analog surround sound (sound card with full complement of six 3.5mm stereo minijacks). HTPC chassis (typically 17"x17"x7") motherboard (mini-ITX), HDD or SSD, Blu-ray drive, PCIe or USB TV tuner card.

bridge

operate in the data link layer (layer 2) if a bridge is aware of destination MAC address, forward packets to the correct segment, otherwise, forwards to all segments. they join similar topologies, used to divide network segments into multiple collision domains. Bridges isolate network traffic, preventing unwanted traffic from entering a segment when there are no recipients on that segment. e.g. 100 device max on an Ethernet segment, bridge can divide segment into two segments of 50 workstations, improving performance. They forward broadcast packets, which is a disadvantage. cannot perform intelligent path selection.

OLED displays

organic light emitting diode. Not just the light source (like LED displays), but also the image producing part of the display. self-contained cells that create light, organic compound placed between an anode and cathode, which run a current through the compound. Thin, lightweight, no need for backlight, less power (unless image processes toward all white), better images in darker surroundings, classified as active matrix or passive matrix.

802.11

original standard defines WLANs transmitting 1Mbps or 2bps using 2.4GHz frequency spectrum, using either frequency hopping spread spectrum or direct sequence spread spectrum for data encoding

OFDM

orthogonal frequency division multiplexing. more efficient data encoding. breaks the data into subsignals and transmits them simultaneously. Occurs on different frequencies or subbands.

resource access models

peer-to-peer, or client-server

token ring

physical star topology, but the traffic flows in a logical ring from one computer to the next.

able locks

physically secure laptop through the use of a cable lock. Kensington lock. K lock.

paper-feed mechanism inkjet

picks up paper from the paper drawer and feeds it into the printer. pickup rollers (several chubby rollers with a flat spot; they rub against the paper as they rotate and feed the paper. work against cork or rubber patches known as separator pads which help keep the paper in place. pickup stepper motor turns a shaft with the pickup rollers. paper-feed sensor tells printer when it is out of paper or paper jam.

568B wiring standard

pin 1: pair 2 white/orange pin2: pair 2 orange pin 3: pair 3 white/green pin 4: pair 1 blue pin 5: pair 1 white/blue pin 6: pair 3 green pin 7 pair 4 brown pin 8: pair 4 white/brown

568A wiring standard

pin 1: pair 3 white/green pin2: pair3 green pin3: pair 2 white orange pin 4: pair1 blue pin5: pair 1 blue/white pin 6: pair 2 orange pin 7: pair 4 white/brown pin 8: pair 4 brown

crossover cable

pin1 to pin3, pin 2 to pin 6 crossed on one side only! This is so send pins match up with receive pins. different on each end.

PDP

plasma display panel. create a plasma cloud from an inert gas such as neon by placing electrodes in front of and behind sealed chambers full of gas and vaporized mercury. running a current through an inert gas. not optimal for high-altitude (aircraft, etc.)

PAT

port address translation. Instead of one-to-one private to public address translation (NAT), allows for many private IP addresses to use one public IP address on the internet.

power sources - laptops

power internal components with DC power; backlights with AC power. Converter to get DC power, inverter to get AC power. Batteries: Nickel cadmium (NiCd), lithium-ion (Li-ion) and nickel-metal hydride (NiM) popular. new lithium-polymer (Li-poly) gainint traction. Energy density (how much energy a battery can hold), and power density (how quickly the stored energy can be accessed).

PRI

primary rate interface (ISDN). 23 B channels and 1D channel. Typically carried on a dedicated T1 connection and is fairly popular in the US. 1,536Kbps (

head carriage - inkjet

print head carriage is the component of the inkjet printer that moves back and forth during printing. contains the physical as well as electronic connections for the print head and ink reservoir.

inkjet- print head/ink cartridge

print head. part of inkjet printer you see most. contains many small nozzles that spray the ink in small droplets onto the page. Most inkjet printers include multiple print heads, one for each CMYK (cyan, magenta, yellow, and black) inks. two methods of spraying: electrical signal sent to heating element, energizing it. the elements heat up quickly, causing the ink to vaporize. because of the expanding ink vapor, the ink is pushed out of the pinhole and forms a bubble, which gets large enough to break off into a droplet. second method: uses piezoelectric element (either a small rod or a unit that looks like a mini drum head) that flexes when energized. the outward flex pushes the ink from the nozzle.

calibration - inkjet

process by which a device is brought within functional specifications. need print heads aligned. printers typically run calibration routine every time you install a new ink cartridge.

public vs. private IP addresses

public addresses must be purchased. only one computer can use any given public address. private addresses are not routable on the internet. In order to access the internet, Network Address Translation (NAT) was created.

printer capacity

quoted in monthly volume. notifies of periodic maintenance.

laser printers

receives instructions one page at a time; uses electrophotographic printing process. (EP). Laser scans the image onto a photosensitive drum. Basic components: toner cartridge, laser scanner, high-voltage power supply, DC power supply, paper transport assembly, transfer corona, fusing assembly, printer controller circuitry, and ozone filter.

plenum-rated coating

refers to Teflon-type coating of coax cables. simply means that the coating does not produce toxic gas when burned.

Super AMOLED / Plus

replaces standard touch sensor panel (TSP) with on-cell TSP that is flat and applied directly to the front of the AMOLED panel, thinner, more sensitive.

CGA

resolutions: 320x200 (4 colors), 640x200 (2 colors)

Paper transport assembly - laser

responsible for moving the paper through the printer. It consists of a motor and several rubberized rollers that each performs a different function. Feed roller or paper pickup roller is D shaped and rotates against the paper and pushes one sheet into the printer. Registration roller (2) synchronize the paper movemenet with the image-formation process in the EP cartridge. Both rollers operated with a special electric motor (electronic stepper motor).

RARP

reverse ARP. resolves MAC addresses to IP addresses.

RRAS

routing and remote access service. Microsoft server-side product to facilitate dial up.

patch cable

same standard on both ends.

RG-6

satellite/cable TV, cable modems. less popular coax, but one of two types still in use today. 1.0mm core, runs longer distances (304 m or 1000 feet), supports digital signals. 75 ohms impedance.

interlacing

scan every other line on each pass using persistence of vision phenomenon instead of scanning every line one at a time on each pass. 1080i refers to interlaced, versus 1080p progressive scanning.

half-duplex

sender and receiver: only one can transmit at a time.

domain

server-based network. security centrally administered. server responsible for security (domain controller).

DMZ

servers that are both public and private, such as web and email servers. separated from internal network by firewall.

primary network components

servers, clients or workstations, resources. every network requiers two or more items to tie these components together: network operating system (NOS), and some kind of shared medium.

SSID

service-set identifier. wireless network's name. wireless access points may connecto to other wireless access points, but eventually connect back to a wired connection.

STP

shielded twisted pair. has an extra layer of braided foil shielding surrounding the wires to decrease electrical interference.

wireless NIC installation

similar to wired nic installation, but must configure to connect to preferred wireless network SSID, configure security settings such as wireless encryption keys.

bus topology

simplest. single cable that runs to every workstation. messages pass through the trunk, and each workstation checks to see if a message is addressed to it. Difficult to add a workstation, if any one of the cables breaks, the entire network is disrupted. Expensive to maintain and difficult to troubleshoot.

LED display

simply LCD panels with light emitting diodes (LEDs) as the light source instead of fluorescent bulbs (legacy). simply the backlight source, not the display technology. individually controlled LEDs can intelligently backlight the screen to enhance the quality of the picture. Operate on DC power.

repeater/extender

small powered device that receives a signal, amplifies it, and sends it on its way. extend functional distance of a cable run. work at the physical layer of the OSI model.

laptop processors

smaller and not quite as powerful. cooling can be an issue: streamlined connection to the motherboard: soldered directly to motherboard in lieu of pins and sockets, or attached using Micro-FCBGA (flip chip ball grid array- balls instead of pins). In most cases, this means that the processor cannot be removed. Lower voltages and clock speeds; active sleep and slowdown modes.

optical drives- laptops

smaller than desktop counterparts. same functionality. drive mechanism and circuits have been miniaturized; cost is higher.

Keyboards- laptops

smaller than standard-sized to fit. lower portion of clamshell. function Fn keys replace some keys on standard kbs.

phablet

smartphone with a display size between 5" and 7"

NIC drivers

software that communicate directly with the OS, specifically the network redirector and adapter interface. Drivers specific to each NIC and OS.

touchscreens - laptops

some requre conductive input (such as your finger), others work with any object touches them.

Bluetooth SIG

special interest roup. 1998. adopted Bluetooth for name of technology. current membership includes Microsoft, intel, apple, ibm, toshiba, several cell phone manufacturers.

refresh rate

specifies how many times in one second the image on the screen can be completely redrawn. count of the screens of info displayed per second. screen draws per second (Hz). higher refresh rate = more fluid motion. LCD TV- refresh rate is typically fixed (120 most common, 60, 240, 480 common as well). refresh rate is selected for the monitor, but can depend on graphics adapter and monitor. If monitor supports only one refresh rate, that's it. higher refresh rates mean lower resolution, vice versa. must be compatible with frame rate.

Standard thick client

standard configuration on which custom configurations are based. (standard client computer system). Must meet recommended req's for selected OS (each has different HW requirements) and be able to run standard desktop applications such as a productivity suite (MS office). Bc it's a client, the ability to attach to a network and accept a configuration that attaches it to one or more servers is implied.

stepper motor and belt - inkjet

stepper motor is a precisely made electric motor that can move in the same very small increments each time it is activated. carriage belt moves the print head back and forth across the page while it prints. rests on a small stabilizer bar.

SVGA

super VGA. resolution: 800x600, 16 colors

SXGA

super XGA, 5:4, 1280x1024

SDSL

symmetric dsl - DL speed 2.5Mbps, UL speed 2.5Mbps

POP3

tcp 110. Post Office Protocol 3. unsecure. Replaced by IMAP4

SMB

tcp 127-139, 445. server message block. Protocol originally developed by IBM. Enhanced by MS, IBM, Intel, etc. used to provide shared access to files, printers, and other network resources. Functions a bit like FTP only with a few more options, ability to connect to printers, more mgmt commands.

IMAP

tcp 143. Internet Message Acces Protocol. Secure protocol designed to download email. Current version is IMAP4. Replaced POP3 (insecure). IMAP4 works in connected and disconnected modes. POP3 - client makes a connection to the email server, downloads email, disconnects. IMAP4- allows client to remain connected to the email server after the download, so as soon as email enters inbox, notified. Allows you to store email on server, POP3 requires download. IMAP4 allows multiple clients to be connected to the same inbox.

FTP

tcp 20,21. file transfer protocol. uploads and downloads files from one host to another. Both a protocol and an application. FTP lets you copy files, list and manipulate directories, and view file contents. Can't use it to execute applications remotely. Users asked to log in. If it's a public site, you can often just use the login anonymous and provide your email address as the password. if using browser such as IE, chrome, firefox, edge, the correct syntax: ftp://username:[email protected]

SSH

tcp 22. Secure Shell. Used to set up a secure Telnet session for remote logins. Encrypts traffic, including user names and passwords. OpenSSH.

Telnet

tcp 23. Terminal Emulation Protocol. Someone using telnet can log into another machine and "see" the remote computer in a window on their screen. Text only. User can manage files on the remote machine. Problem is that the data they transmit including passwords, is sent in plain text.

SMTP

tcp 25. Simple Mail Transfer Protocol is the protocol most commonly used to send email messages. Designed to send only (push protocol). Used to send email from mail server to mail server and from server to email client. Email client locates its email server by querying the DNS server for a mail exchange (MX) record. After the server is located, SMTP is used to push the message to the mail server, which processes the message for delivery.

RDP

tcp 3389. Remote Desktop Protocol. allows users to connect to remote computers and run programs on them. You see the desktop of the comp you've signed into on your screen. The computer at which you are seated is client and computer you're logging into is the server. Server uses video driver to create video output sent over RDP. Keyboard and mouse input encrypted and sent to the server for processing. Supports sound, drive, port, and network printer redirection.

LDAP

tcp 389. lightweight directory access protocol. directory services protocol based on X.500 standard. Designed to access information stored in an information directory typically known as LDAP directory. Info such as employee phone books, email addresses, client contact lists, infrastructure and config data for the network and network applications. LDAP provides you with access to these databases (ACLs control who can access/change entries)

AFP

tcp 427, 548. Apple Filing Protocol. developed in 1980s for use with AppleTalk network protocol. file transfer protocol similar to FTP and SMB. default file transfer protocol for Msc OS until SMB2 in 2013.

HTTPS

tcp 443. Hypertext Transfer Protocol Secure. use either SSL or TLS to secure transmission. Encrypts data across wire. To use HTTPS, the website needs to obtain an SSL certificate from a reputable certificate authority.

HTTP

tcp 80. hypertext transfer protocol. Most commonly used. Manages communication between web server and client and lets you connect to and view all of the content that you enjoy on the Internet. All info transmitted in plain text, not secure.

DNS

tcp/udp 53. Domain name system. resolves hostnames to IP addresses.

subnet mask

tells where network ID ends and host ID begins. Any bit set to 1 = network ID. 0 = host ID. To communicate, devices must have an IP address and correct subnet mask.

contrast ratio

the measure of the ratio of the luminance of the brightest color to the darkest color that the screen is capable of producing. Not the same as contrast, which is an adjustable setting. Contrast ratios are fixed measurements that become selling points for the monitors. LCD displays tend to have low contrast ratios, and only LED backlit LCD panels rival the high contrast ratios that plasma displays have. smaller LCD monitors/tvs- 500:1, common ratios for larger LCD units: 20,000:1-100,000:1. LED backlit: common 1,000,000:1. dynamic ratio: reducing power to the backlight for darker images.

inkjet

these printers spray ink on the page to form the image. typically use a reservoir of ink, a pump, and a nozzle to accomplish this. older ones were messy, noisy, and inefficient, but the technology is better now. also called bubble-jet printers. contain few parts: print head/ink cartridge, head carriage, belt, and stepper motor, paper-feed mechanism, control, interface, and power circuitry.

BNC connector

thinnet cables connect to BNC connector, attached to T-shaped connector that attached to the workstation. The other side of the T-connector would either continus on with another thinnet segment or be capped off with a terminator.

3G

third generation technology. max speed 500Kbps downloads.

fusing assembly

toner has negative static charge and most objects have a net positive charge. therefore, toner sticks, but needs a fuser to apply pressure and heat to fuse the plastic toner particles to the paper.

toner cartridge - laser

toner is a black carbon substance mixed with polyester resins to make it flow better and iron oxide particles to make it sensitive to electrical charges. toner is capable of being attracted to the photosensitive drum and of melting into the paper. Can hold a static charge when not exposed to light, cannot hold a charge when it is exposed to light.

LCD panel construction- Twisted Nematic

twisted nematic (TN)- less expensive, less color accurate, more reaction to touch, narrow viewing angle, less power. places electrodes on opposite sides of a liquid crystal layer, when electrical field is generated by electrodes, the crystals aligh perpendicular to the electrodes, and allow light to pass straight through, unseen by observer. When electrodes are off, crystals rotate parallel and passing light 90 degrees and visible to observer's eye. Shifts the colors as observer views the screen from wide angles. also react to pressure. faster response rates and more fluid image changes

wiring standards twisted pair

twisted pair cables use multiple physical wires- need to be in the right places in the rj-45 connector. two standards: 568A and 568B.

UTP

two or four pairs of twisted wires and plenum or pvc coating. Standard transmission length: 100m. (10Gbps over cat 6 is55). Also referred to as ethernet cables. Comes in several grades to offer different levels of performance/protection against electrical interference. Cat 1, 2, 3, 4, 5, 5e, 6, 6a, 7

scatternet

two or more piconets (up to 8 devices each) connected with one or more devices serving as a bridge between piconets.

UTP Cat 1

two twisted pairs. voice only transmissions. legacy phone system.

fiber-optic cable

two varieties: single-mode or multimode.

IPS - laptops

type of LCD technology. In-Plane Switching. LCD monitor provides better color represnetation and wide viewing angle than TN.

TN - laptops

type of LCD technology. Twisted Nematic. Older of the two technologies, relatively inexpensive, lower power. Viewing at wide angles: picture quality suffers.

dot-matrix printers

type of impact printer. instead of a spinning character imprinted wheel, the print head contains rows of pins that are triggered in patterns to form letters and numbers. To trigger a pin, the printer controller sends a signal to the print head, which energizes the wires around the appropriate print wire, which turns the print wire into an electromagnet, which repels the print pin, forcing it against the ink ribbon and making a dot on the paper. disadvantage: image quality. "draft quality". near letter quality NLQ. Noisy, but quieter than daisy wheel. Faster - 72cps. some can print at close to a page per second.

SNMP

udp 161. Simple Network Management Protocol. Gathers and manages network performance info. SNMP server can be set up to collect data from network devices (agents) and ensure that your network is iperating properly. SNMPv3 most current.

DHCP

udp 67, 68. dynamic host configuration protocol (DHCP). dynamically assigns IP addresses and other IP configuration information to network clients. Reduces network administration headaches.

unicast address IPv6

unicast address identifies a single node on the network.

impact printers

use some form of impact and an inked ribbon to make an imprint on the paper. alsu use a paper feed mechanism called a tractor feed that requires special paper. holes running down both edges. Daisy wheel and dot matrix.

thermal printers

used in POS terminals and older fax machines. print on special kind of waxy paper that comes on a roll; the paper turns black when heat passes over it. Print head is the width of the paper. Heating element heats certain spots on the print head. Te paper below the heated print head turns black in those spots.

F connector

used with cable tv / coax cable. the exposed end of the copper cable is pushed into the receptacle, and the connector is threaded so that it can screw into place.

splitter

used with coax. takes a single signal and splits it into multiple replicas of the same signal. Could be used for cable TV or cable internet. Splitting signal can weaken it, might not travel the same distance.

single mode fiber

uses only a single mode of light to propogate through the fiber cable. commonly used in phone systems. travels straight down the fiber and does not bounce off walls. lower bandwidth at longer distances. lasers generate light. up to 10Gbps for up to 40km (25.85 miles).

satellite internet

uses satellite dish to receive data from an orbiting satellite and relay station that is connected to the internet. max out around 10 to 15Mbps. weather and line-of-sight requirements = occasional disruption of service. propogation delay or latency occurs bc the length of time required to transmit the data and receive response. 250-350 milliseconds. 35,000 km into space.

dual scan (display)

variation of passive-matrix display. The screen is split in half and the passive matrix technique is implemented on both halves. each half refreshed separately. still, cannot match active matrix for image quality and viewing angle.

VDSL

very high bit-rate dsl = DL speed 52Mbps, UL speed 16Mbps

video card - laptops

video card in laptop with lcd monitor does the same thing a video card supporting a CRT monitor would do. generates and manages the image sent to the screen. but LCD monitors are digital, so video card outputs digital image. Most laptop manufacturers integrate the LCD circuitry on the motherboard to safe space. odds are video card shares memory with the processor.

VDU types

video display types: liquid crystal display LCD, Plasma, OLED, Projection systems

Infrared

walk up, point to point interconnection standard,. low cost, interoperable. requires line of sight. 1 meter distance limitation.

DHCP discover

when DHCP configured client boots up, it sends out a broadcast on the network requesting a DHCP server. server initially responds to the request and fulfills the request by returning info to client.

Ethernet over power

when it's not possible to run cables for a network connection and wireless is a problem. uses electrical outlets; adapter. Both devices must be on the same electrical circuit.

WPA

wi-fi protected access. uses TKIP (temporal key integrity protocol) instead of static key. 128-bit dynamic per-packet key, so new key generated for each packet. Message integrity checking.

WXGA

widescreen xga 16:10, 1280x800

WEP

wired equivalent privacy. first security standard. encrypts data to provide data security with a static key. Keys are commonly 10, 26, or 58 hexadecimal characters long. static keys/weak encryption: 2 -3 min to crack.

WLAN

wireless LAN . standards managed by IEEE

WAP

wireless access point. looks similar to wireless router, but cannot share an internet connection. Need a wireless router for that.

fitness monitor

worn on wrist, normally. tracks a user's movements and heart rate.

Audio jack

Early optical drives required special cable attached to rear of drive. Cable then attached to sound card that was attached to speakers. Now 3.5mm jack on faceplate rerouted audio to headphones or speakers.

FSB speed

Effective clock rate. How front side bus uses clock. Cpu multiplies fab speed to calculate internal clock rate.

Memory bank

Eight memory chips in a set; each chip stores mil/bil of bits of info, each in own cell. For every byte in memory, one bit stored in each of 8 chips. 9th chip added to support parity system if applicable.

Coaxial

Either baseband (single frequency, terminated by RCA or BNC plugs) or broadband (seen in cable tv settings, multiple frequencies, requires tuning/demodulation equipment, F connectors).

Mini DisplayPort

Electronically equivalent to full size version, no latching mechanism.

eMMC drive

Embedded flash memory (multimedia card). Can be permanently embedded in primary circuit board of a cheaper/smaller device. Cannot compete with SSD, however, bc it doesn't have the fast interfaces and firmware. SSDs use multiple flash memory chips as an array, like how RAID uses multiple drives.

Heat pipes

Enclosed systems that employ tubing filled with liquid. Tubes attached to device they are cooling; dissipates heat. Particularly beneficial in smaller devices/laptops.

ECC

Error correcting code. If memory supports ecc, check bits are generated and stored with data, algorithm performed so that result of algorithm is all zeros. Checked whenever the memory accessed. If only one but error per byte, ecc can fix it. If two bit error per byte, ecc can recognize error.

RJ 45 splitters

Ethernet splitters. takes the incoming signal on two pairs and then splits it, so on the output end it produces two sets of signals using two pairs each. because of this, Ethernet splitters are limited to 100Mbps.

Network Access layer (physical, data link)

Ethernet, Fast Ethernet, Token Ring, FDDI

CSMA/CD

Ethernet. Carrier Sense (computers are listening on the wire at all times) Multiple access (multiple comps have access to the line at the same time) collision detection (the collision is detected and each sender knows they need to send again, waits short random period and then retransmits. Larger than 100 comps on same network, more collisions than connections.

Even/odd parity

Even/odd parity operate on every byte. Even parity: if number of "ones" is even, store 0 in parity bit. If number is odd, store 1 in parity bit to make even. Odd parity is opposite.