Ethernet

Ethernet is one of the most common forms of network cable used on wired networks. It is used in a variety of scenarios, such as connecting patch panels to switches in the form of patch cables, connecting a wall outlet to a desktop, and connecting infrastructure devices such as routers and switches. In this section we’ll look at its various implementations.

568A/B

Two wiring standards are commonly used with twisted-pair cabling: T568A and T568B (sometimes referred to simply as 568A and 568B). These are telecommunications standards from TIA and EIA that specify the pin arrangements for the RJ-45 connectors on UTP or STP cables. The number 568 refers to the order in which the wires within the Cat 5 cable are terminated and attached to the connector. The signal is identical for both.

T568A was the first standard, released in 1991. Ten years later, in 2001, T568B was released. Figure 3.1 shows the pin number assignments for the 568A and 568B standards. Pin numbers are read left to right, with the connector tab facing down. Notice that the pin-outs stay the same, and the only difference is in the color coding of the wiring.

The bottom line here is that if the same standard is used on each end, the cable will be a crossover cable, and if a different standard is used on either end, it will be a straight-through cable. Crossover cables are used to connect like systems such as two computers or two switches or two routers.

   Mixing cable types can cause communication problems on the network. Before installing a network or adding a new component to it, make sure the cable being used is in the correct wiring standard.

Fiber

Fiber-optic cabling is the most expensive type of those discussed for this exam. Although it’s an excellent medium, it’s often not used because of the cost of implementing it. It has a glass core within a rubber outer coating and uses beams of light rather than electrical signals to relay data (see Figure 3.2). Because light doesn’t diminish over distance the way electrical signals do, this cabling can run for distances measured in kilometers with transmission speeds from 1 Gbps up to 100 Gbps or higher.

Coaxial

Coaxial cable, or coax, is one of the oldest media used in networks. Coax is built around a center conductor or core that is used to carry data from point to point. The center conductor has an insulator wrapped around it, a shield over the insulator, and a nonconductive sheath around the shielding. This construction, depicted in Figure 3.3, allows the conducting core to be relatively free from outside interference. The shielding also prevents the conducting core from emanating signals externally from the cable.

Speed and transmission limitations

Table 3.1 lists the speed and transmission limitations for the most common fiber-optic implementations.

VGA

This is the traditional connector for the display of a computer, and it is shaped like a D. It has three rows of five pins each, for a total of 15 pins. This is also often called the HD-15 (also known as DB-15) connector. A VGA cable carries analog signals. The cable length utilized will affect the resolution achieved: 1024×768 would operate more effectively with 30 feet or less of cable length. As the need for resolution increases, the allowable maximum cable length decreases. Figure 3.4 shows a VGA port.

HDMI

High-Definition Multimedia Interface (HDMI) connectors are used to connect compatible digital items (DVD players and conference room projectors, for example). The Type A connector has 19 pins and is backward-compatible with DVI (discussed later in this chapter). Type B connectors have 29 pins and aren’t backward compatible with DVI, but they support greater resolutions. Type C connectors are a smaller version of Type A for portable devices. Type D is an even smaller micro version that resembles a micro-USB connector. Type E is planned for use in automotive applications. HDMI has a theoretical cable length limit of 45 feet or 15 meters. Figure 3.5 shows all HDMI types.

There are several versions of HDMI, as described in Table 3.2.

Mini-HDMI

A Mini HDMI port is used on DSLR cameras and standard sized tablets. It differs only in the physical size of the connector. Both are shown in Figure 3.6.

DisplayPort

DisplayPort is a digital interface standard produced by the Video Electronics Standards Association (VESA), used for audio and video. The interface is primarily used to connect a video source to a display device such as a computer monitor or television set. It resembles a USB connector (see Figure 3.7). Its supports a 1.62, 2.7, 5.4, or 8.1 Gbps data rate per lane; 1, 2, or 4 lanes; (effective total 5.184, 8.64, 17.28, or 25.92 Gbps for 4-lane link); 1 Mbps or 720 Mbps for the auxiliary channel.

DVI

There are several types of Digital Video Interface (DVI) pin configurations, but all connectors are D-shaped. The wiring differs based on whether the connector is single-linked or dual-linked (extra pins are used for the dual link). DVI differs from everything else in that it includes both digital and analog signals at the same time, which makes it popular for LCD and plasma TVs. Maximum cable length is 16 feet (5 meters).

DVI connectors can come in several forms, known as DVI-D, DVI-I, and DVI-A. DVI can sometimes do analog and digital at the same time. Figure 3.8 shows the various types of DVI plugs discussed in this section.

The single link maximum data rate including 8b/10b overhead is 4.95 Gbps at 165 MHz. With the 8b/10b overhead subtracted, the maximum data rate is 3.96 Gbps.

Dual link maximum data rate is twice that of single link. Including 8b/10b overhead, the maximum data rate is 9.90 Gbps at 165 MHz. With the 8b/10b overhead subtracted, the maximum data rate is 7.92 Gbps.

DVI-D

DVI-D (the D stands for digital) connectors supply digital signals only. These can also come in a single- or dual-link format. A dual-link format allows for a second data link.

DVI-I

A DVI-I connector (the I stands for integrated) has pins that can provide analog and digital. These can also come in a single- or dual-link format.

DVI-A

A DVI-A connector (the A stands for analog) has pins that can provide analog and digital. This type comes in a single-link format only.

Lightning

Apple uses what it calls the Lightning connector for power. Although it makes an adapter to convert this connector to mini-USB (see the next section), Apple doesn’t encourage its use because of the limitations the adapter places on the functionality of the proprietary connector.

This is an eight-pin connector that while not standard has advantages over USB, according to Apple. It operates at USB 3.0 speeds of 640 MB. The following are some of these advantages:

• It can supply more power.
• It can be inserted either way.
• It is physically more durable than USB.
• It can detect and adapt to connected devices.

Figure 3.9 shows a Lightning connector next to a USB cable.

Thunderbolt

Thunderbolt ports are most likely to be found on Apple laptops, but they are now showing up on others as well. Figure 3.10 shows a Thunderbolt port on an HP laptop. Notice the “thunderbolt” icon next to the port. Thunderbolt has a maximum speed of 10 Gbps, Thunderbolt 2 has a maximum speed of 20 Gbps, and Thunderbolt 3 has a maximum speed of of 40 Gbps, compared to 800 Mbps for Firewire 800, 5 Gbps for USB 3.0, and 10 Gbps for USB 3.1.

The Thunderbolt cable is shown in Figure 3.11.

USB

USB is an expansion bus type that is used almost exclusively for external devices. All motherboards today have at least two USB ports. Some of the advantages of USB include hot-plugging and the capability for up to 127 USB devices to share a single set of system resources. A USB port requires only one IRQ for all USB devices that are connected to it, regardless of the type or number of devices.

Connector types: A, B, mini, micro

USB connectors come in two types and two form factors or sizes. The type A connector is what is found on USB hubs, on host controllers (cards that are plugged into slots to provide USB connections), and on the front and back panels of computers. Type B is the type of USB connector found on the end of the cable that plugs into the devices.

The connectors also come in a mini version and a micro version. The micro version is used on mobile devices, such as mobile phones, GPS units, PDAs, and digital cameras, whereas the mini is found in applications described in the previous paragraph. The choice between a standard A and B and a mini A and B will be dictated by what is present on the device. The cables used cannot exceed 5 meters in length. Figure 3.12 shows, from left to right, a standard Type A, a mini Type A, a standard Type B, and a mini Type B. Some manufacturers have chosen to implement a mini connector that is proprietary, choosing not to follow the standard.

USB-C

The USB-C connectors connect to both hosts and devices, replacing various USB-B and USB-A connectors and cables with a standard. This type is distinguished by its two-fold rotationally symmetrical connector. The cable is shown in Figure 3.13 next to USB 3.0 cable.

USB 2.0/3.0

USB 1.1 runs at 12 Mbps and USB 2.0 runs at 480 Mbps.

USB 3.0 has transmission speeds of up to 5 Gbps, significantly reduces the time required for data transmission, reduces power consumption, and is backward-compatible with USB 2.0. Because USB is a serial interface, its width is 1 bit. It is useful to note, however, that a USB 2.0 device will perform at 2.0 speeds even when connected to a 3.0 port.

By utilizing USB hubs in conjunction with the USB ports available on the local machine, you can connect up to 127 of these devices to the computer. You can daisy-chain up to four external USB hubs to a USB port. Daisy chaining means that hubs are attached to each other in a line. A USB hub will not function if it is more than four hubs away from the root port.

Serial

Although an older cable type, a serial connector may be found connecting some peripherals to the serial connection on the system. This cable is shown in Figure 3.14. The maximum speed is 115200 bps.

SATA

Serial AT Attachment (SATA) drives are AT Attachment (ATA) drives that use serial transmission as opposed to parallel. They use a different cable because of this. It is not a ribbon cable but a smaller cable. Both implementations can operate up to 16 GB. Figure 3.15 shows the data cable and its connector.

SATA Internal SATA storage devices have 7-pin data cables and a 15-pin power cable.

eSATA eSATA cables may be either flat or round and can be only 2 meters (6 feet) in length. An eSATA connector is shown in Figure 3.16.

IDE

IDE drives are the most common type of hard drive found in computers. But IDE is much more than a hard drive interface; it’s also a popular interface for many other drive types, including CD-ROM, DVD, and Zip drives. IDE drives are easy to install and configure, and they provide acceptable performance for most applications. Their ease of use relates to their most identifiable feature—the controller is located on the drive itself. The IDE drive along with its data and power cables is shown in Figure 3.17.

The design of the IDE is simple: Build the controller right on the drive and use a relatively short ribbon cable to connect the drive/controller to the IDE interface. This offers the benefits of decreasing signal loss (thus increasing reliability) and making the drive easier to install. The IDE interface can be an expansion board, or it can be built into the motherboard, as is the case on almost all systems today.

IDE generically refers to any drive that has a built-in controller. The IDE you know today is more properly called AT IDE; two previous types of IDE (MCA IDE and XT IDE) are obsolete and incompatible with it.

There have been many revisions of the IDE standard over the years, and each one is designated with a certain AT attachment (ATA) number—ATA-1 through ATA-8. Drives that support ATA-2 and higher are generically referred to as enhanced IDE (EIDE). Here are some of the highlights: With ATA-3, a technology called ATA Packet Interface (ATAPI) was introduced to help deal with IDE devices other than hard disks. ATAPI enables the BIOS to recognize an IDE CD-ROM drive, for example, or a tape backup or Zip drive. Starting with ATA-4, a new technology was introduced called UltraDMA, supporting transfer modes of up to 33 Mbps. ATA-5 supports UltraDMA/66, with transfer modes of up to 66 Mbps. To achieve this high rate, the drive must have a special 80-wire ribbon cable. The drive in Figure 3.17 shows the 40-pin cable, and the motherboard or IDE controller card must support ATA-5. ATA-6 supports UltraDMA/100, with transfer modes of up to 100 Mbps.

ATA-7 supports UltraDMA/133, with transfer modes of up to 150 Mbps and SATA.

ATA-8 made only minor revisions to ATA-7 and also supports UltraDMA/133, with transfer modes of up to 600 Mbps and SATA.

Table 3.3 lists the ATA standards and their details.

SCSI

Small Computer System Interface (SCSI) is most commonly used for hard disks and tape drives, but it can connect a wide range of other devices, including scanners and CD drives. These devices reside on a single bus, which must be terminated on either end. Eight or sixteen devices can be attached to a single bus (with number one taken by the host bus controller), depending on whether the SCSI bus is wide (0–15) or narrow (0–7) bus. There also is a host bus controller, which is usually plugged into a slot in the computer or can be integrated into the motherboard. Figure 3.18 shows an internal SCSI connector.

DVI to HDMI

These adapters connect from HDMI to DVI and come in a number of gender combinations (male DVI to female HDMI, male DVI to male HDMI, female DVI to male HDMI, and so on) and as either a cable or simply an inline connector. Figure 3.19 shows an inline connector.

USB to Ethernet

These converters allow you to use a USB port as a network interface. They come both as cables and as inline connectors. Figure 3.20 shows an example of a USB-to-Ethernet adapter.

DVI to VGA

In cases where you need to convert DVI to VGA, you can use a DVI-to-VGA adapter. These come as a cable or inline connectors and also come in a variety of gender combinations. Figure 3.21 shows an example of the ends of this adapter.

SODIMM

Portable computers (notebooks and subnotebooks) require smaller sticks of RAM because of their smaller size. One of the two types used is small outline DIMM (SODIMM), which can have 72, 144, or 200 pins, while desktops use a full-size DIMM. Figure 3.27 earlier shows the form factors for 72- and 144-pin SODIMMs.

DDR

Double Data Rate (DDR) is clock-doubled SDRAM. The memory chip can perform reads and writes on both sides of any clock cycle (the up, or start, and the down, or ending), thus doubling the effective memory executions per second. So, if you’re using DDR SDRAM with a 100 MHz memory bus, the memory will execute reads and writes at 200 MHz and transfer the data to the processor at 100 MHz. The advantage of DDR over regular SDRAM is increased throughput and thus increased overall system speed.

DDR2

DDR SDRAM is Double Data Rate 2 (DDR2). This allows for two memory accesses for each rising and falling clock and effectively doubles the speed of DDR. DDR2-667 chips work with speeds at 667 MHz and are also referred to as PC2-5300 modules.

DDR3

The primary benefit of DDR3 over DDR2 is that it transfers data at twice the rate of DDR2 (eight times the speed of its internal memory arrays), enabling higher bandwidth or peak data rates. By performing two transfers per cycle of a quadrupled clock, a 64-bit-wide DDR3 module may achieve a transfer rate of up to 64 times the memory clock speed in megabytes per second. In addition, the DDR3 standard permits chip capacities of up to 8 GB.

DDR4

DDR4 SDRAM is an abbreviation for double data rate fourth-generation synchronous dynamic random-access memory. DDR4 is not compatible with any earlier type of random-access memory (RAM). The DDR4 standard allows for DIMMs of up to 64 GB in capacity, compared to DDR3’s maximum of 8 GB per DIMM. Higher bandwidths are achieved by sending more read/write commands per second. To allow this, the standard divides the DRAM banks into two or four selectable bank groups so that transfers to different bank groups may be done more rapidly. Table 3.5 lists the selected memory standards, speeds, and formats.

Parity vs. Nonparity

RAM is supplied either with no parity (8 data bits per byte) or with parity (8 data bits and 1 parity bit per byte, for a total of 9 bits per byte). If present, parity bits are used to determine whether data moving to and from memory has been corrupted or damaged (thus changed) in the transmission. You can identify parity SIMMs by counting the number of chips on the stick. If there are nine, it’s parity RAM. If there are eight, it’s nonparity.

When do you choose parity RAM? Usually, the motherboard requires either parity or nonparity RAM; a few motherboards will accept either. Nowadays, parity RAM is needed only in highly critical computing tasks because advances in RAM technology have created reliable RAM that seldom makes errors.

ECC vs. Non-ECC

Another type of RAM error correction is Error Correction Code (ECC). RAM with ECC can detect and correct errors. As with parity RAM, additional information needs to be stored, and more processing needs to be done, making ECC RAM more expensive and a little slower than nonparity and parity RAM. Both ECC and parity memory work in ECC mode. However, ECC memory does not work in plain parity checking mode because the extra bits cannot be individually accessed when ECC memory is used. This type of parity RAM is now obsolete. Most RAM today is non-ECC.

CD-ROM/CD-RW

CD-ROM stands for Compact Disc Read-Only Memory. The CD-ROM media is used for long-term storage of data. CD-ROM media is read-only, meaning that once information is written to a CD, it can’t be erased or changed. Access time for CD-ROM drives is considerably slower than for a hard drive. Standard CDs normally hold 650 MB to 700 MB of data and use the ISO 9660 standard, which allows them to be used on multiple platforms.

Compact Disc-ReWritable (CD-RW) media is a rewritable optical disc. A CD-RW drive requires more sensitive laser optics. It can write data to the disc but also has the ability to erase that data and write more data to the disc. It does this by liquefying the layer where the data resides (removing the reflectivity placed there by the writing process used to create the old data) and then creating new reflectivity in the same layer upon writing again that represents the new data. Two states of reflectivity are used to represent the 0s and 1s for the data. CD-RWs cannot be read in some CD-ROM drives built prior to 1997.

DVD-ROM/DVD-RW/DVD-RW DL

Because DVD-ROM drives use slightly different technology than CD-ROM drives, they can store up to 4.7 GB of data in a single-layer configuration. This makes DVDs a better choice than CDs for distributing large software bundles. Many software packages today are so huge that they require multiple CDs to hold all the installation and reference files. A single DVD, in a double-sided, double-layered configuration, can hold as much as 17 GB (as much as 26 regular CDs).

As you might expect, the primary advantage of DVD-RW drives over DVD-R drives is the ability to erase and rewrite to a DVD-RW disc. In these drives, a layer of metal alloy on the disk is manipulated to erase and write the data, rather than burning into the disc itself, similar to the operation of CD-RW.

A dual-layer DVD-RW disc employs a second physical layer within the disc itself. The drive with dual-layer capability accesses the second layer by shining the laser through the first semitransparent layer.

Blu-ray

Blu-ray recorders have been available since 2003, and they have the ability to record more information than a standard DVD using similar optical technology. In recent years, Blu-ray has been more synonymous with recording television and movie files than data, but the Blu-ray specification (1.0) includes two data formats: BD-R for write-once and BD-RE for rewritable media (more later in this section). BD-J is capable of more sophisticated bonus features than provided by standard DVD, including network access, picture-in-picture, and access to expanded local storage. With the exception of the Internet access component, these features are called Bonus View. The addition of Internet access is called BD Live.

The current capacity of a Blu-ray is 100 GB. As a final note, there was a long-running (but finally complete) battle between Blu-ray and HD DVD to be the format of the future, and Blu-ray won.

BD-R

Blu-ray players have two data formats: BD-R for recording computer data and BD-RE for rewritable media. BD-R can be written to only one time.

BD-RE

Blu-ray Disc Recordable Erasable (BD-RE) can be erased and written to multiple times. Disc capacities are 25 GB for single-layer discs, 50 GB for double-layer discs, 100 GB for triple-layer discs, and 128 GB for quad-layer discs.

M2 drives

M.2, formerly known as the Next Generation Form Factor (NGFF), is a specification for internally mounted computer expansion cards and associated connectors. It replaces the mSATA standard. M.2 modules are rectangular, with an edge connector on one side and a semicircular mounting hole at the center of the opposite edge. They can use PCI-Express, Serial ATA, and USB 3 connectors The M.2 standard allows module widths of 12, 16, 22, and 30 mm, and lengths of 16, 26, 30, 38, 42, 60, 80, and 110 mm.

NVME

NVM Express (NVMe) or Non-Volatile Memory Host Controller Interface Specification (NVMHCIS) is an open logical device interface specification for accessing nonvolatile storage media attached via a PCI Express (PCIe) bus. It allows host hardware and software to fully exploit the levels of parallelism possible in modern SSDs. The latest version is 1.3c.

SATA 2.5

SATA revision 2.5 consolidated the specification to a single document.

5,400 rpm

The rotational speed of the disk or platter has a direct influence on how quickly the drive can locate any specific disk sector on the drive. This locational delay is called latency and is measured in milliseconds (ms). The faster the rotation, the smaller the delay will be. A drive operating at 5,400 rpms will experience about 5.5 ms of this delay.

7,200 rpm

Drives that operate at 7,200 rpm will experience about 4.16 ms of latency. A typical 7,200 rpm desktop hard drive has a sustained data transfer rate up to 1,030 Mbps. This rate depends on the track location, so it will be higher for data on the outer tracks and lower toward the inner tracks.

10,000 rpm

At 10,000 rpm, the latency will decrease to about 3 ms. Data transfer rates also generally go up with a higher rotational speed but are influenced by the density of the disk (the number of tracks and sectors present in a given area).

15,000 rpm

Drives that operate at 15,000 rpm are higher-end drives and suffer only 2 ms of latency. These drives also generate more heat, requiring more cooling to the case. They also offer faster data transfer rates for the same areal density.

Sizes: 2.5/3.5

Magnetic hard drives come in two sizes, 2.5 inch and 3.5 inch. Smaller drives are for laptops, while the larger size is for desktop computers.

SD card

Secure Digital (SD) cards are just one type of flash; there are many others. The maximum capacity of a standard SD card is 512 GB, and there are two other standards that go beyond this: Secure Digital High Capacity (SDHC) can go to 32 GB and Secure Digital Extra Capacity (SDXC) to 2 TB. Figure 3.35 shows a Compact Flash card (the larger of the two) and an SD card along with an eight-in-one card reader/writer. The reader shown connects to the USB port and then interacts with Compact Flash, Compact Flash II, Memory Stick, Memory Stick PRO, SmartMedia, xD-Picture cards, SD, and MultiMediaCards. The SD card specification defines three physical sizes, discussed in the following sections.

CompactFlash

Compact Flash (CF) cards are a widely used form of solid-state storage. There are two main subdivisions of CF cards: Type I (3.3-mm thick) and the thicker Type II (CF2) cards (5-mm thick). CF cards can be used directly in a PC card slot with a plug adapter, used as an ATA (IDE) or PCMCIA storage device with a passive adapter or with a reader, or attached to other types of ports such as USB or FireWire. Figure 3.35 shows a CF card.

Micro-SD card

Micro-SD is the smallest of the three. It is 11 mm × 15 mm × 1 mm.

Mini-SD card

Mini-SD is the middle child of the three SD form factors shown in Figure 3.36. It is 20 mm × 21.5 mm × 1.4 mm.

xD

xD-Picture card is a flash memory card format, used mainly in older digital cameras. xD stands for Extreme Digital. xD cards are available in capacities from 16 MB up to 2 GB. Pictures are transferred from a digital camera’s xD card to a PC by plugging the camera into the USB or IEEE 1394 (FireWire) cable or by removing the card from the camera and inserting it into a card reader. Figure 3.37 shows an xD card.

IDE configuration and setup (master, slave, cable select)

The primary benefit of IDE is that it’s nearly universally supported. Almost every motherboard has IDE connectors.

A typical motherboard has two IDE connectors, and each connector can support up to two drives on the same cable. That means you’re limited to four IDE devices per system unless you add an expansion board containing another IDE interface. In contrast, with SCSI (covered in the next section), you can have up to seven drives per interface (or even more on some types of SCSI).

Performance also may suffer when IDE devices share an interface. When you’re burning CDs, for example, if the hard drive you are reading from is on the same cable as the CD drive you are writing to, errors may occur. SCSI drives are much more efficient with this type of transfer.

To install an IDE drive, do the following:

1. Set the master/slave jumper on the drive.
2. Install the drive in the drive bay.
3. Connect the power-supply cable.
4. Connect the ribbon cable to the drive and to the motherboard or IDE expansion board. Ensure that the master device is closest to the connection to the motherboard.
5. Configure the drive in BIOS Setup if it isn’t automatically detected.
6. Partition and format the drive using the operating system.

Each IDE interface can have only one master drive on it. If there are two drives on a single cable, one of them must be the slave drive. This setting is accomplished via a jumper on the drive. Some drives have a separate setting for Single (that is, master with no slave) and Master (that is, master with a slave); others use the Master setting generically to refer to either case. The Cable Select setting will assume you have the primary drive first and secondary drive second on the cable. Figure 3.38 shows a typical master/slave jumper scenario, but different drives may have different jumper positions to represent each state. Today, the need for jumper settings has decreased because many drives can autodetect the master/slave relationship.

Most BIOS Setup programs today support plug and play, so they detect the new drive automatically at startup. If this doesn’t work, the drive may not be installed correctly, the jumper settings may be wrong, or the BIOS Setup may have the IDE interface set to None rather than Auto. Enter BIOS Setup and find out. All you usually have to do is set the IDE interface to Auto and allow the BIOS to detect the drive.

In BIOS Setup for the drive, you might have the option of selecting a Direct Memory Access (DMA) channel or Programmed Input/Output (PIO) setting for the drive. Both are methods for improving drive performance by allowing the drive to write directly to RAM, bypassing the CPU when possible. For modern drives that support Ultra Direct Memory Access (UltraDMA), neither of these settings is necessary or desirable. The Ultra DMA interface is the fastest method used to transfer data through the ATA controller, usually between the computer and an ATA device.

When the drive is installed, you can proceed to partition and format it for the operating system you’ve chosen. Then, you can install your operating system of choice.

For a Windows 10 system, allow the Windows Setup program to partition and format the drive (when installing the operating system), or use the Disk Management utility in Windows to perform those tasks. To access Disk Management, from the Control Panel choose Administrative Tools and then Computer Management.

RAID 0, 1, 5, 10

RAID stands for Redundant Array of Independent (or Inexpensive) Disks. It’s a way of combining the storage power of more than one hard disk for a special purpose such as increased performance or fault tolerance. RAID is more commonly done with SCSI drives, but it can be done with IDE or SATA drives. This section outlines the most common types of RAID. Because of the methods used to provide fault tolerance, the total amount of usable space in the array will vary, as discussed for each type.

RAID 0 RAID 0 is also known as disk striping. This is technically not RAID because it doesn’t provide fault tolerance. Data is written across multiple drives, so one drive can be reading or writing while the next drive’s read/write head is moving. This makes for faster data access. However, if any one of the drives fails, all content is lost. In RAID 0, since there is no fault tolerance, the usable space in the drive is equal to the total space on all the drives. So if the two drives in an array have 250 GB each of space, 500 GB will be the available drive space. RAID 0 is shown in Figure 3.39.

RAID 1 RAID 1 is also known as disk mirroring. This is a method of producing fault tolerance by writing all data simultaneously to two separate drives. If one drive fails, the other drive contains all the data and may also be used as a source of the data. However, disk mirroring doesn’t help access speed, and the cost is double that of a single drive. Since RAID 1 repeats the data on two drives, only one half of the total drive space is available for data. So if two 250 GB drives are used in the array, 250 GB will be the available drive space. RAID 1 is shown in Figure 3.40.

RAID 5 RAID 5 combines the benefits of RAID 0 and RAID 1 and is also known as striping with parity. It uses a parity block distributed across all the drives in the array, in addition to striping the data across them. That way, if one drive fails, the parity information can be used to recover what was on the failed drive. A minimum of three drives is required. RAID 5 uses 1/n (n = the number of drives in the array) for parity information (for example, one-third of the space in a three-drive array), and only 1 (1/n) is available for data. So if three 250 GB drives are used in the array (for a total of 750 GB), 500 GB will be the available drive space. RAID 5 is shown in Figure 3.41.

RAID 10 RAID 10 is also known as RAID 1+0. Striped sets are mirrored (a minimum of four drives, and the number of drives must be even). It provides fault tolerance and improved performance but increases complexity. Since this is effectively a mirrored stripe set and a stripe set gets 100 percent use of the drive without mirroring, this array will provide half of the total drive space in the array as available drive space. For example, if there are four 250 GB drives in a RAID 10 array (for a total of 1 TB), the available drive space will be 500 GB. RAID 10 is shown in Figure 3.42.

Hot swappable

If a drive can be attached to the PC without shutting down the PC, it is described as a hot-swappable drive. Drive types that are hot-swappable include USB, FireWire, SATA, and those that connect through Ethernet. You should always check the documentation to ensure that your drive supports this feature.

ATX

An older but still used form factor, Advanced Technology Extended (ATX), provided many design improvements over the previous version, the AT. These improvements include I/O ports built directly into the side of the motherboard, the CPU positioned so that the power-supply fan helps cool it, and the ability for the PC to be turned on and off via software. It uses a PS/2-style connector for the keyboard and mouse, which is rarely used today because USB keyboards are used. Newer ATX models have removed PS/2 connectors. The expansion slots are parallel to the narrow edge of the board. See Figure 3.43.

mATX

The mini-ATX has dimensions of 15 cm × 15 cm (5.9 in × 5.9 in) and is slightly smaller than the mini-ITX (discussed in the next section). It was originally part of the ATX specification but was removed after the introduction of micro-ATX. It uses less power, generates less heat, and fits into a single DIN space.

ITX

The Information Technology eXtended (ITX) motherboards—the mini-ITX, nano-ITX, and pico-ITX—were proposed by VIA Technologies. The mini-ITX fits in the same case as the micro-ATX; uses low power, which means it can be passively cooled (no fan); and has one expansion slot. The nano-ITX is even smaller; it is used for set-top boxes, media centers, and car computers. The pico-ITX is even smaller again, half the size of the nano-ITX. It uses daughter cards (extensions of the motherboard) to supply additional functionality.

Figure 3.44 compares common motherboard types and their sizes.

mITX

Mini-ITX is a 17 cm × 17 cm (6.7 in × 6.7 in) motherboard. It is commonly used in small-configured computer systems.

PCI

The Peripheral Component Interconnect (PCI) bus is a fast (33 MHz), wide (32-bit or 64-bit) expansion bus that was a modern standard in motherboards for general-purpose expansion devices. Its slots are typically white. PCI devices can share interrupt requests (IRQs) and other system resources with one another in some cases. You may see two PCI slots, but most motherboards have gone to newer standards. Figure 3.45 shows some PCI slots.

PCI cards that are 32-bit with 33 MHz operate up to 133 MBps, whereas 32-bit cards with 64 MHz operate up to 264 MBps. PCI cards that are 64-bit with 33 MHz operate up to 266 MBps, whereas 64-bit cards with 66 MHz operate up to 538 MBps.

PCIe

PCI Express (PCIE, PCI-E, or PCIe) uses a network of serial interconnects that operate at high speed. It’s based on the PCI system; you can convert a PCIe slot to PCI using an adapter plug-in card, but you cannot convert a PCI slot to PCIe. Intended as a replacement for AGP and PCI, PCIe has the capability of being faster than AGP while maintaining the flexibility of PCI. There are five versions of PCIe: Version 1 is up to 8 GBps, version 2 is up to 16 GBps, version 3 is up to 32 GBps, version four is up to 64 GBps, and version five up to 128 GBps. Figure 3.46 shows the slots discussed so far in this section.

miniPCI

Laptops and other portable devices utilize an expansion card called the miniPCI. It has the same functionality as the PCI but has a much smaller form factor. Unlike portable PCM-CIA cards, which are inserted externally into a slot, these are installed inside the case. Figure 3.47 shows a miniPCI card alongside a miniPCI Express card. Table 3.6 lists the specifications of all the slot types discussed in this section.

Riser card

Although it isn’t common, you may occasionally encounter a slim-line case, which is a desktop-oriented case that is shorter and thinner than a normal one—so short that normal expansion boards won’t fit perpendicular to the motherboard. In such cases a riser card is installed, which sits perpendicular to the motherboard and contains expansion slots. The expansion cards can then be oriented parallel to the motherboard when installed. So, it’s a card that hosts other cards. Figure 3.48 shows a riser card from two angles.

Socket types

To review, there are two basic socket types now on the board, Serial ATA and IDE.

Front panel connector

There are a number of interfaces, buttons, lights, and audio jacks in the front panel of the computer that must be connected to the board for power and functionality. This section discusses each of these and their respective methods of connection to the motherboard.

Internal USB connector

When USB ports exist on the front panel (as they almost always do these days), they must be connected to the motherboard so that the connected USB device can communicate with the computer. This is done with a 10-pin connector located on the board, as shown in Figure 3.49.

Audio

When audio plugs or jacks exist in the front panel, as they do in most computers now, they must be connected to the motherboard if you are using the integrated sound card. (Otherwise, they may connect directly to the sound card.) Figure 3.49 shows an example of the audio plug on the board.

Power button

The power button located in the front panel must also be connected to the motherboard to communicate on/off information to the computer. This connector is located along with the remaining connectors discussed in this section, clustered in a group on the motherboard in the section labeled “Front-panel connection cluster” in Figure 3.49.

Power light

The power indicator light must also be provided with power and a connection to the board. It is also located in the section labeled “Front-panel connection cluster” in Figure 3.49.

Drive activity lights

The drive activity light, which indicates when a hard drive is being either read or written to, must have a connection to the motherboard both for power and to transmit the drive activity information. It is also located in the section labeled “Front-panel connection cluster” in Figure 3.49.

Reset button

The reset button, like all the other front-panel components, has a connection to the motherboard and is located in the section labeled “Front-panel connection cluster” in Figure 3.49.

Boot options

Each system has a default boot order, which is the order in which it checks the drives for a valid operating system to which it can boot. Usually, this order is set for the hard disk and then CD-ROM, but these components can be placed in any boot order. For example, you might set CD-ROM first to boot from a disk that already contains an operating system. If you receive an error message when booting, always check the CD-ROM, and if a nonsystem disk is present, remove it and reboot.

Firmware updates

Computer BIOSs don’t go bad; they just become out-of-date or contain bugs. In the case of a bug, an upgrade will correct the problem. An upgrade may also be necessary when the BIOS doesn’t support some component that you would like to install—a larger hard drive or a different type of processor, for instance.

Most of today’s BIOSs are written to an electrically erasable programmable read-only memory (EEPROM) chip and can be updated through the use of software. Each manufacturer has its own method for accomplishing this. Check out the documentation for complete details. Regardless of the exact procedure, the process is referred to as flashing the BIOS. It means the old instructions are erased from the EEPROM chip and the new instructions are written to the chip.

UEFI is a standard firmware interface for PCs, designed to replace BIOS. Some advantages of UEFI include the following:

• Better security, which protects the preboot process
• Faster startup times and resuming from hibernation
• Support for drives larger than 2.2 TB
• Support for 64-bit firmware device drivers
• Capability to use BIOS with UEFI hardware

UEFI can also be updated by using an update utility from the motherboard vendor. In many cases, the steps are as follows:

1. Download the update file to a flash drive.
2. Insert the flash drive and reboot the machine.
3. Use the specified key sequence to enter the BIOS settings.
4. If necessary, disable secure boot.
5. Save the changes and reboot.
6. Reenter the BIOS settings.
7. Choose boot options, and boot from the flash drive.
8. Follow the specific directions with the update to locate the upgrade file on the flash drive.
9. Execute the file (usually by typing flash).
10. While the update is completing, ensure that you maintain power to the device.

Security settings

A number of security features are built into most BIOSs. They include BIOS passwords, drive encryption, Trusted Platform Module (TPM), and LoJack. These items are discussed in this section.

BIOS Passwords In most CMOS Setup programs, you can set a supervisor password. Doing so requires a password to be entered in order to use the CMOS Setup program, effectively locking out users from making changes to it. You may also be able to set a user password, which restricts the PC from booting unless the password is entered.

To reset a forgotten password, you can remove the CMOS battery to reset everything. There also may be a Reset jumper on the motherboard. The CMOS battery is shown in Figure 3.53 later in the chapter.

Drive Encryption Many operating systems provide the ability to encrypt an entire volume or drive, protecting a mobile device’s data in the event of theft. A good example of this is BitLocker, which is available in Windows 10. The drives are encrypted with encryption keys, and the proper keys are required to boot the device and access the data.

BitLocker can be used with a TPM chip (discussed in the next paragraph), but it is not required. When this feature is in effect with no TPM chip, the keys are stored on a USB drive that must be presented during startup to allow access to the drives. Without the USB drive holding the key, the device will not boot.

TPM Chips When the device has a TPM chip present on the motherboard, additional security and options become available. First the chip contains the keys that unlock the drives. When the computer boots, the TPM chip unlocks the drive only after it compares hashes of the drive to snapshots of the drive taken earlier. If any changes have been made or tampering has been done to the Windows installation, the TPM chip will not unlock the drives.

Moreover, you can (and should) combine this with a PIN entered at startup or a key located in a USB drive. In this scenario, the computer will not start unless the hashes pass the test and the PIN or key is provided.

LoJack LoJack is a product made by Absolute Software that allows you to remotely locate, lock, and delete the data on a mobile device when it is stolen. It is a small piece of software that embeds itself on the computer and is difficult to detect. Once activated, it stays in contact with a monitoring center, allowing you to send the commands to lock and delete data via the center. Not only can you protect the data in this fashion, but it will also gather forensic data that can help to locate the device and aid in its recovery.

Secure Boot Secure Boot is a standard adopted by many vendors that requires the operating system to check the integrity of all system files before allowing the boot process to proceed. By doing so, it protects against the alteration or corruption of these system files. As with any emerging technology, issues have already been discovered that can enable a hacker to not only bypass Secure Boot but to also change a key value in the settings that will “brick” the device (render it useless).

Interface configurations

There are settings in the BIOS that can affect several components including the voltage, clock, and bus speed. At startup, the BIOS will attempt to detect the devices and components at its disposal. The information that it gathers, along with the current state of the components, will be available for review in the BIOS settings. Some of the components and the types of information available with respect to these devices and components are covered in this section.

You can view and adjust a computer’s base-level settings through the CMOS Setup program, which you access by pressing a certain key at startup, such as F1 or Delete (depending on the system). The most common settings to adjust in CMOS include port settings (parallel, serial, USB), drive types, boot sequence, date and time, and virus/security protections. The variable settings that are made through the CMOS Setup program are stored in nonvolatile random-access memory (NVRAM), while the base instructions that cannot be changed (the BIOS) are stored on an EEPROM chip. NVRAM is memory that does not lose its content when power is lost to the machine. Figure 3.50 shows an example of NVRAM on a motherboard.

Voltage

You can also monitor and change the voltage settings in the BIOS. Be cautious in changing these settings, because improper settings can damage the system or shorten the life of the CPU. Possible settings include the following:

• CPU voltage
• Memory voltage, which will typically be 1.5 volts
• Motherboard voltage
• Voltage of the graphics card

These are just a few examples. Figure 3.51 shows an example of these and many more voltage settings.

Clock

The CMOS clock is located on the computer’s motherboard and keeps time when the computer is off. The operating system gets its time from the BIOS clock at boot time. This clock can be set using the BIOS if it is not correct. Figure 3.52 shows the time setting.

Bus Speed

The processor’s ability to communicate with the rest of the system’s components relies on the supporting circuitry. Part of the system board’s underlying circuitry is called the bus. The computer’s bus moves information into and out of the processor and other devices. A bus allows all devices to communicate with one another. The motherboard has several buses. The external data bus carries information to and from the CPU and is the fastest bus on the system. The address bus typically runs at the same speed as the external data bus and carries data to and from RAM. The address bus gives the address to which the data should go. The data bus uses the address supplied by the address bus and carries the data to the specified location. The PCI, AGP, and ISA interfaces also have their own buses with their own widths and speeds. With newer architectures, the system or front-side bus (FSB) connects the CPU to the north bridge (or memory) hub. The back-side bus (BSB) connects the CPU with the Level 2 (L2) cache, also called the secondary or external cache. The memory bus connects the north bridge (or memory) hub to RAM.

The bus speed, like the CPU speed, can also be set. (See the discussion of the relationship between the bus speed, the CPU speed, and the multiplier in the section “Speeds” later in this chapter.) Usually, this should be left alone because it is normally set to a setting proper for the memory, but it can be changed. In many systems, this must be done with jumpers on the motherboard.

Single-Core/ Multicore

CPUs can have a single core, or they can be dual-core, quad-core, or even dual-quad-core (eight CPUs total). When multiple cores exist, they operate as individual processors, so the more the better. The largest boost in performance will likely be noticed in improved response time while running CPU-intensive processes, such as virus scans, ripping/burning media (requiring file conversion), or file searching.

The addition of more cores does not have a linear effect on performance. The potential impact of multiple cores also depends on the amount of cache or memory present to serve the CPU. When a computer is designed for the processor, this will have been taken into consideration, but when adding a multicore processor to a PC, it is an issue to consider.

Virtual technology

When using virtualization technology, a fuller realization of its benefits can be achieved when the processor supports this concept.

The benefit derived from this support is to allow the virtualization product (also called a hypervisor) to use hardware-assisted virtualization. This allows the hypervisor to dynamically allocate CPU to the virtual machines (VMs) as required. Both AMD and Intel offer CPUs that support hardware virtualization.

Hyperthreading

One feature available since the Pentium 4 is hyperthreading technology. This feature enables the computer to multitask more efficiently between CPU-demanding applications. An advantage of hyperthreading is improved support for multithreaded code, allowing multiple threads to run simultaneously and thus improving reaction and response time.

Speeds

Clock speed is a measurement of the rate at which the clock signal oscillates; it is expressed in millions of cycles per second or megahertz. The motherboard must be set to utilize the proper clock settings for the CPU installed in the computer. The BIOS usually detects the type of CPU and automatically sets the proper timings. In some older systems, you may have to use jumpers to set the correct clock speed and CPU.

External Speed (Clock Speed) The clock speed, or external speed, which is usually expressed in megahertz or gigahertz, is the speed at which the motherboard communicates with the CPU. It’s determined by the motherboard, and its cadence is set by a quartz crystal (the system crystal) that generates regular electrical pulses.

Internal Speed The internal speed is the maximum speed at which the CPU can perform its internal operations. This may be the same as the motherboard’s speed (the external speed), but it’s more likely to be a multiple of it. For example, a CPU may have an internal speed of 1.3 GHz but an external speed of 133 MHz. That means for every tick of the system crystal’s clock, the CPU has 10 internal ticks of its own clock.

When the proper CPU speed is known, you must make sure the relationship between the speed of the CPU and that of the motherboard bus is correct. This is done with a value called the multiplier. Although the bus speed can also be manipulated, usually it is set to accommodate the required speed of the memory to be used, and so it is more likely you will be using the multiplier to achieve the proper relationship between the CPU speed and the bus speed.

For example, if you have a processor that has a CPU speed of 1.82 GHz, the proper settings for the BIOS would be a bus speed of 166 MHz and a multiplier of 11 (166 MHz × 11 = 1.826 GHz). So if the bus needed to be 166 MHz, you would set the multiplier for 11. On the other hand, if you changed the bus speed to 332 MHz (just a random example), the closest multiplier would be 5.5 to maintain 1.826 GHz (332 MHz × 5.5 = 1.826 GHz). When setting the speed of either is required, refer to the documentation from the CPU and motherboard.

Overclocking

Overclocking is when you set the bus speed using a multiplier that is higher than recommended or is specified in the documentation. An overclocked device may be unreliable or fail completely if the additional heat load is not removed or power delivery components cannot meet increased power demands. Many device warranties state that overclocking and/or over-specification voids any warranty.

Integrated GPU

A graphics processing unit (GPU) is a specialized circuit designed to rapidly manipulate and alter memory to accelerate the building of images in a frame buffer intended for output to a display. It improves the graphic abilities of the PC when this feature is present in the CPU.

Some visual features provided by operating systems such as Windows 10 are unavailable unless the CPU has dedicated graphics memory or a GPU. For example, the Aero view in Windows 10 requires a card capable of DirectX, which is a technology that requires the DirectCompute API, which in turn requires a GPU.

AMD

Advanced Micro Devices (AMD) is one of two major processor vendors in the world. Athlon models are AMD processors. See Table 3.7 for models and socket compatibility.

Intel

The market leader in chip manufacturing is Intel Corporation, with Advanced Micro Devices (AMD) gaining a market share in the home PC market. Here’s a quick list of socket types from both manufacturers you may encounter:

Intel: LGA 775, 1155, 1156, 1366, 1150, 2011 Earlier in this chapter, Table 3.7 lists the various Intel CPU slots and sockets you may find in a motherboard and explains which CPUs will fit into them.

AMD: AM3, AM3+, FM1, FM2, FM2+ Table 3.7 also lists the various AMD CPU slots and sockets you may find in a motherboard and which CPUs will fit into them. These later-generation AMD sockets were launched as the successor to Socket AM2+. In 2009, AMD3 was released alongside the initial grouping of Phenom II processors designed for it. The principal change from AM2+ to AM3 is support for DDR3 SDRAM. The AM3+ socket has been designed for the AMD FX series Zambezi processors based on the Bulldozer architecture. Socket FM2 is a CPU socket launched in September 2012. Motherboards using the FM2 utilize AMD’s new A85X chipset. The FM2+ uses three PCI Express cores: one 2×16 core and two 5×8 cores, for a total of 64 lanes.

CPU Sockets

The CPU slot permits the attachment of the CPU to the motherboard, allowing the CPU to use the other components of the system. There are many different types of processors, meaning there are many types of CPU connectors.

The CPU slot can take on several different forms. In the past, the CPU slot was a rectangular box called a pin grid array (PGA) socket, with many small holes to accommodate the pins on the bottom of the chip. With the release of new and more powerful chips, additional holes were added, changing the configuration of the slot and its designator or number. Figure 3.54 shows a typical PGA-type CPU socket.

With the release of the Pentium II, the architecture of the slot went from a rectangle to more of an expansion-slot style of interface called a single-edge contact cartridge (SECC). This style of CPU slot includes Slot 1 and Slot 2 for Intel CPUs and Slot A for Athlon (AMD) CPUs. This type of slot looks much like an expansion slot, but it’s located in a different place on the motherboard from the other expansion slots. Figure 3.55 shows an SECC.

To see which socket type is used for which processors, examine Table 3.7. This list is not exhaustive. Some of the slots may fit processors that are not specifically listed.

Sockets are the interface with which CPUs are plugged into the motherboard. These sockets have evolved over the years along with the changes in CPU architecture and design. There are three form factors for CPU chips: pin grid array (PGA), single-edge contact cartridge (SECC), and land grid array (LGA). The PGA style is a flat square or rectangular ceramic chip with an array of pins in the bottom. The actual CPU is a silicon wafer embedded inside that ceramic chip. The SECC style is a circuit board with the silicon wafer mounted on it. The circuit board is then surrounded by a plastic cartridge for protection; the circuit board sticks out of the cartridge along one edge. This edge fits into a slot in the motherboard.

Fans

Active heat sinks have a fan that sits atop the heat sink. It pulls the heat out of the heat sink and away from it. Then the case fan shunts the heat out the back or side of the case.

Heat Sink

The cooling can be either active or passive. A passive heat sink is a block of heat-conductive material that sits close to the CPU and wicks away the heat into the air. An active heat sink contains a fan that pulls the hot air away from the CPU. The heat sink sits atop the CPU, in many cases obscuring it from view entirely.

Liquid

Liquid-based cooling cases are available that use circulating water rather than fans to keep components cool. These cases are typically more expensive than standard ones and may be more difficult for a technician untrained in this technology to work on, but they result in an almost completely silent system.

Issues with liquid-based cooling machines can include problems with hoses or fittings, the pump, or the coolant. A failure of the pump can keep the liquid from flowing and cause the system to overheat. A liquid-based cooling system should also be checked every so often for leaks or corrosion on the hoses and fittings, and the reservoir should be examined to make sure it is full and does not contain contaminants. Liquid-based cooling is more expensive, less noisy, and more efficient than Peltier components.

Thermal paste

Most passive heat sinks are attached to the CPU using a glue-like thermal compound (called thermal glue, thermal compound, or thermal paste). This makes the connection between the heat sink and the CPU more seamless and direct. Thermal compound can be used on active heat sinks, too, but generally it isn’t because of the possibility that the fan may stop working and need to be replaced. Thermal compound improves thermal transfer by eliminating tiny air pockets between the heat sink and CPU (or other device like a north bridge or video chipset). Thermal compound provides both improved thermal transfer and adds bonding for heat sinks when there are no mounting holes to clamp the heat sink to the device to be cooled.

Video cards

PCs today also contain internal video cards, but as with sound cards, you can achieve better video quality with more expensive video cards. This is especially true when the video card has its own dedicated memory.

Add-on card

Video cards can be installed in the AGP, PCI, and PCIe slots. At one point, the best choice was clear, and that was the AGP slot. However, the newer PCIe slots provide more bandwidth. AGP provides a wider data path because it’s parallel, whereas PCIe is serial. But PCIe now goes up to 16,000 MBps as compared to AGP, which is 2,000 MBps. Figure 3.56 shows the AGP slot next to some slots you have already learned about.

Some of the special functions you may get with a more expensive video card are 3D imaging, MPEG decoding (decoding simply means it can interpret this file type), and TV output. The ability to use multiple monitors is also built into many cards.

Sound cards

Most computers these days come with an integrated sound card, but for more robust sound or advanced features, you may need to install a sound card. Sound cards can be either internal or external. Internal cards require opening the case and installing the card in a slot. External cards plug into the USB socket.

In some cases, an audio cable will be connected from the card to the CD-ROM. This is rarely required these days. Figure 3.57 shows the connectors present on most sound cards today.

Network interface card

Network cards do exactly what you would think; they provide a connection for the PC to a network. In general, network interface cards (NICs) are added to a PC via an expansion slot or they are integrated into the motherboard, but they may also be added through a USB or PCMCIA slot (also known as PC card). The most common issue that prevents network connectivity is a bad or unplugged patch cable.

Network cards are made for Ethernet, fiber-optic, token ring (rarely used now), and 802.11 (wireless) connections. The Ethernet, token ring, and fiber-optic cards accept the appropriate cable, and the wireless cards have radio transmitters and antennas.

The most obvious difference between network cards is the speed of which they are capable. Most networks today operate at 100 MBps or 1 GBps. Regardless of other components, the PC will operate at the speed of the slowest component, so if the card is capable of 1 GBps but the cable is capable of only 100 MBps, the PC will transmit only at 100 MBps.

Another significant feature to be aware of is the card’s ability to perform autosensing. This feature allows the card to sense whether the connection is capable of full duplex and to operate in that manner with no action required.

There is another type of autosensing, in which the card is capable of detecting what type of device is on the other end and changing the use of the wire pairs accordingly. For example, normally a PC connected to another PC requires a crossover cable, but if both ends can perform this sensing, that is not required. These types of cards are called auto-MDIX.

USB expansion card

Universal Serial Bus (USB) expansion cards are used to provide a USB connection (or an additional connection) to a PC that has none (pretty rare today). All modern motherboards today have at least two USB slots. Some of the advantages of USB include hot-plugging and the capability for up to 127 USB devices to share a single set of system resources. USB 1.1 runs at 12 Mbps, and USB 2.0 runs at 480 Mbps. Because USB is a serial interface, its width is 1 bit. USB 3.0 specifies a maximum transmission speed of up to 5 Gbps (625 MBps), which is more than 10 times as fast as USB 2.0 (480 Mbps), although this speed is typically achieved only by using powerful, professional-grade or developmental equipment.

These cards are made to plug into PCI, PCIe, or PCMCIA slots.

eSATA card

eSATA provides a form of SATA meant for external connectivity. SATA (discussed more completely earlier in the section “eSATA”) is used for drive connections internally on many PCs. eSATA uses a more robust connector, longer shielded cables, and stricter (but backward-compatible) electrical standards. The interface resembles that of USB and IEEE 1394 (FireWire), but the cable cannot be as long, and the cable does not supply power to the device. The advantage it has over the other technologies is speed—it is approximately three times as fast as either FireWire or USB 2.0 (although USB 3.0 is faster).

An eSATA card is shown in Figure 3.58. This card offers two eSATA slots on the part of the card that extends out the back of the system.

Lumens/brightness

When discussing bulbs for projectors, brightness is a description of light output, which is measured in lumens (not watts). Ensure that you are purchasing the correct bulb for the projector and maximize the life of the bulb by turning the projector off when not in use.

SATA

The SATA power connector has 15 pins, with 3 pins designated for 3.3 V, 5 V, and 12 V and with each pin carrying 1.5 amps. This results in a total draw of 4.95 watts + 7.5 watts + 18 watts, or about 30 watts. Figure 3.64 shows the SATA power connector.

Molex

A Molex connector is used to provide power to drives of various types. It has four pins, two of which have power (one 12 V and the other 5 V). These are standard for IDE (PATA) or older SCSI drives. The total power demands are from 5 to 15 watts for IDE and 10 to 40 watts for SCSI. The four-pin Molex connector was shown in Figure 3.26 earlier.

Four/eight-pin 12 V

With the introduction of the Pentium 4, motherboards began to require more power. Supplemental power connections were provided to the motherboard in 4-, 6- (discussed later in this section), or 8-pin formats. These were in addition to the 20-pin connector (also discussed later) that was already provided.

There is a four-pin square mini version of the ATX connector, which supplies two pins with 12V, and an eight-pin version (two rows) that has four 12V leads. These connect to other items, such as the processor, or to other components, such as a network card that may need power that exceeds what can be provided with the ATX connection to the board. Figure 3.65 shows the eight-pin version and the four-pin square mini version.

PCIe six/eight-pin

PCIe slots also draw more power and require power in addition to the main 20-pin connector (discussed next). These additional connectors can be six pins and may also contain an additional two-pin connector on the side for cases where the connection required is eight-pin.

20-pin

The main ATX connector, referenced earlier, is a 20-pin connector. The four pins carrying power are 3.3V, 3.3V, 5V, and 5V. This allows the motherboard to pull about 20 to 30 watts. Figure 3.66 shows the 20-pin ATX.

24-pin

The 24-pin ATX connector is simply the 20-pin connector discussed earlier along with the extra 4-pin connector on the side. This provides the four pins carrying power as discussed earlier plus an additional four pins with 5V standby, 12V,12V, and 3.3. Figure 3.67 shows the 24-pin ATX.

Multicore processor

The resource-intensive applications used with graphics, CAD, and CAM require high-end multicore processors. For example, to run a 64-bit version of Autodesk AutoCAD software, you need a 64-bit 1 GHz processor. Keep in mind this is only the minimum. For good performance, this minimum should be exceeded.

High-end video

As you can imagine, the video demands of graphics such as 3D are much higher than those of common office applications. Continuing with the example of AutoCAD 2012, this requires a 1360 × 768 true-color video display adapter. Note that the graphics card should have a minimum of 128 MB of VRAM for its operations.

Maximum RAM

There can never be enough RAM, and in the case of CAD/CAM and graphics, the minimum (using the same example) is 4 GB of RAM. When the minimum to run the software is 2 GB, you need much more than that for good performance.

Specialized audio and video card

Many video- and audio-editing software packages come with a special capture card that works in concert with the accompanying software to provide ease of use. For example, it might be an internal PCI card that captures video from any analog or DV source. You can also output video to a VCR or an analog or DV camcorder from this card. They still require (you guessed it) a high-end audio and video card as well and plenty of memory and a processor that may not have quite the requirements of CAD/CAM but still should be 2.4 GHz or higher.

Large, fast hard drive

Your hard drive should be at least 7,200 rpm. You will also want at least two drives if not three. When doing audio, use one for the operating system and programs and a second drive for audio files. When doing video, consider a third drive used exclusively for video files.

Even better, consider a RAID setup. Many motherboards include a SATA RAID controller built in. Use RAID 0 to enhance performance (see the section “RAID 0, 1, 5, and 10” under objective 3.4).

Dual monitors

Especially when doing video editing, a second monitor is well worth the money and the desk real estate. You may need to read or refer to something on one screen while using the other for the editing software. The material could be tutorials or source material.

It also may be that you should move your tools (for example, Photoshop controls) to one screen so they don’t clutter the image you are working on.

Maximum RAM and CPU cores

The amount of RAM that is required depends on the number of VMs that you anticipate operating at the same time, not on how many exist on the desktop. Total the memory requirements of each VM that will be open at the same time, in addition to the requirements of the host operating system. That should be the minimum. Then add more for overhead to ensure performance.

The memory issue is not something you can fudge. If there is not enough memory, the VM will not start, and you will be notified with an error message that there is insufficient memory.

With regard to CPU, it should be dual- if not quad-core, and multiple CPUs would be even better.

Multicore processor

When it comes to the processor, the question becomes “How much do you want to spend?” Just as a comparison (prices change daily!), for almost $10,000 you can get the 878151-L21 HPE Xeon Platinum 8160M 24 Core 2.10GHz LGA. Also keep in mind that multiple processors or multicore processors will always improve the gaming experience.

High-end video/specialized GPU

When playing a game, it is critical that the action you are seeing (and reacting to) is rendered to the screen as quickly as possible. With gaming machines, dual GPU cards are often used. The higher-end cards also require water cooling of GPUs. In fact, the faster cards all need water cooling (covered later in this section).

High-definition sound card

When you’re considering the features of a sound card, you want those features to be performed in hardware. Anytime these functions are performed in software, it simply means the main CPU is going to get the workload. Also, you want to go with a high-definition card. The following are things to consider:

• Using the PCI Express slot (better bandwidth) is better than using the PCI slot.
• Make sure the card has its own onboard memory (less work for the main CPU).
• If you are using a Mac, a Thunderbolt card is the way to go.

High-end cooling

With all the heat being generated by the CPUs and GPUs, fans may not be sufficient to remove the heat. Water-cooling systems will cool the system better and will be quieter as well. Cooling kits circulate water through the case in tubes that enter and exit the box to a unit where the water is cooled again (think of the cooling system in your car). Figure 3.68 shows a cooling system.

Desktop applications

A thick client has the applications installed locally and will need to have sufficient resources to support the applications. Applications state these requirements in the documentation. With a thick client, since all application support will come from the local machine, these requirements must be met to use the software.

Meets recommended requirements for selected OS

A standard thick client will need to provide all the hardware requirements of the installed operating system. This is because unlike the thin client (discussed in the next section) none of the processing will be offloaded to a server. It all must be supplied by the thick client. Requirements for various operating systems are covered in Chapter 6, “Operating Systems.”

Basic applications

Some applications are created to function in a client-server architecture. When these are used in a thin client, the client side of the application operates on the thin client but requires minimal system resources. The server side of the application performs all the processing, and the client side simply renders the output to the display and transmits keystrokes to the server.

Meets minimum requirements for selected OS

Even thin client operating systems have minimum requirements. Follow the documented requirements to ensure good performance. In many cases, older computers that would be of no use as thick clients are suitable candidates to be thin clients.

Network connectivity

Most traditional thin clients come with a NIC built in. They require the same settings that any networked device does, including IP address, subnet mask, and default gateway. These can be static configuration, or the device can receive these through Dynamic Host Configuration Protocol (DHCP).

Media streaming

The home server can act as a streaming media server to other computers in the home network if the operating system provides this capability. An example of such an operating system is Windows Home Server. Once the streaming feature is enabled, other systems can use their Windows Media Players to connect to any shared content and stream that content to the other PC. One of the benefits of this is centralized storage of content and reduced duplication of the content on other machines in the network. This type of server should have plenty of disk space and memory.

File sharing

For the same reasons that centralized storage of media content reduces content duplication in the network, so can file sharing from a home server. Another great benefit of this is a central location to perform regular backups of the files so that this does not need to be done on all the other machines in the network. This server should have plenty of disk space.

Gigabit NIC

When a machine is acting as the home server for all these functions, the network card will be busy. For that reason, it is probably a good idea to ensure that it is a Gigabit NIC, which allows it to operate 10 times faster than the standard 100 MB NIC. Make sure that the cabling supports 1 GB, or you will be wasting your time and money.

RAID array

To speed the access to data or to provide fault tolerance to any data stored on the home server, consider using multiple hard drives and implementing a RAID 0, RAID 1, or RAID 5 hard disk system. See the section “RAID 0, 1, 5, and 10” under objective 3.4.

Thin client

The thin client must have a network configuration. In most cases you should use DHCP for this. If you have a wireless router, it can issue these configurations. For better performance, however, plug the thin client into the Ethernet ports that typically come with ISP-provided routers. If DHCP is not in use, ensure that the thin client has an IP configuration that will enable it to connect to the server and to other required resources including the Internet.

Thick client

Treat the installation of the thick client in the same way you would the thin client. If you have a wireless router, it can issue these configurations. For better performance, however, plug the thick client into the Ethernet ports that typically come with ISP-provided routers. If DHCP is not in use, ensure that the thick client has an IP configuration that will enable it to connect to required resources including the Internet.

Account setup/settings

On both thin and thick clients you must create user accounts and passwords for those who will be using the device. Ensure accountability by using no shared accounts. Each user should have a unique username/password combination.

Touchpad configuration

Touchpads do not typically need configuration and were covered in detail in Chapter 1, “Mobile Devices.”

Touchscreen configuration

Touchscreens sometimes need calibration. Calibration is a process that varies by vendor but is usually requires touching the screen in certain places when it tells you to. See the documentation on the exact method.

Application installations/configurations

It is likely that the system will not have all required applications installed. Just as you must ensure that the system has sufficient resources (memory, CPU, storage space) for the operating system, you must do the same for the applications. Also, be mindful of how the applications will be used. If multiple applications will be in use simultaneously, ensure that resources are sufficient to run all of them effectively at the same time.

Synchronization settings

Some data types may need to be synchronized across the various locations where they may be stored. Synchronization is covered in Chapter 1.

Account setup/settings

Treat the setup of accounts and their security the same with a laptop as you would with the desktop. Ensure accountability by using no shared accounts. Each user should have a unique username/password combination.

Wireless settings

Laptops often are moved around and use WLAN connections. To support this, the wireless card should be set for DHCP, as each wireless AP you encounter will provide an IP configuration that works on that WLAN.

Also ensure that you have a WLAN profile created for any WLAN you will connect to that has a hidden SSID. Enter any required credentials and save them in the profile to save the user the aggravation of entering this each time they are connected.

Configuration settings

You need to be familiar with the various settings that are available and what these settings do. This section covers the more common settings, features, and characteristics of printers.

Duplex An optional component that can be added to printers (usually laser but also inkjet) is a duplexer. This can be an optional assembly added to the printer, or built into it, but the sole purpose of duplexing is to turn the printed sheet over so it can be run back through the printer and allow printing on both sides.

Collate Collating is the process of arranging the output of a print job so that multiple individual sets of the output are in proper order. A collator is a unit that if present on the printer will allow the printer to collate.

Orientation The orientation of a document refers to how the printed matter is laid out on the page. In the landscape orientation, the printing is written across the paper turned on its long side, while in portrait the paper is turned up vertically and printed top to bottom.

Quality Print quality is a description of the look of the printing, its sharpness, and its color depth. It is impacted by the quality of the paper, the speed of the printing process, and the resolution settings. It can also be affected by the DPI setting. This setting controls the size of objects on the page and therefore their sharpness. As you increase the size of an object, its quality will usually decrease a bit.

Wired

The wired forms of connection this exam tests on are USB, parallel, serial, and Ethernet. Each is addressed in the sections that follow.

Wireless

The wireless forms of connection included on this exam are Bluetooth, 802.11x, and Infrared (IR). Each is addressed in the sections that follow.

Integrated print server (hardware)

A print server is a popular option for adding a printer to the network and not adding a host computer. To be a print server, the NIC in the printer differs from a NIC in a computer in that it has a processor on it to perform the management of the NIC interface, and it is made by the same manufacturer as the printer.

For a printer to qualify as a print server, when someone on the network prints, the print job must go directly to the printer and not through any third-party device. This tends to make printing to that printer faster and more efficient—that NIC is dedicated to receiving print jobs and sending printer status to clients.

Cloud printing/remote printing

While printing remotely to a printer over the Internet has been available for a number of years, cloud printing is a new service being offered by cloud vendors. In a cloud arrangement, you connect your printer to the vendor’s cloud, and then the printer is available to you anywhere you can get Internet access, just as cloud-based resources are available anywhere you can get Internet access.

While cloud-ready printers are not required, cloud vendors encourage their use in this arrangement. These are printers that need no PC to connect to the Internet, which makes the process of connecting to the cloud print server much simpler.

Another option is to create a VPN connection to your home network. Once connected to the home network over the VPN, you should be able to connect to and print to the printer as if you were sitting in your home office.

Sharing local/networked device via operating system settings

To share a local/networked printer via the Windows operating systems, right-click the icon for the printer (beneath Devices And Printers or Printers And Faxes, depending on your operating system) and choose Printer Properties. Next, click the Sharing tab.

Select Share This Printer and provide a name that the printer will be known by on the network. This is the name that will appear when adding a new network printer on a client, and it can also be referenced by the entire qualified name using the syntax \hostshare_name.

Data privacy

In any scenario where users are sharing a device, data privacy is an issue. There are several things that can be done to protect the privacy of data sent to the printer.

• Ensure that all users are authenticated to the device (discussed next).
• Ensure that users are given only the rights to the device they need to perform their job.
• Consider the use of data loss prevention (DLP). These services can be used to control the printing, emailing, sharing, or deleting of documents.

Make use of the auditing features to maintain an awareness of who does what and when they do it.

Imaging drum, fuser assembly, transfer belt, transfer roller, pickup rollers, separate pads, duplexing assembly

First let’s discuss the major components used in the laser printing process and then discuss the process steps. An EP (laser) printer consists of the following major components:

Printer Controller This is a large circuit board that acts as the motherboard for the printer. It contains the processor and RAM to convert data coming in from the computer into a picture of a page to be printed.

Imaging Drum The toner cartridge and drum are typically packaged together as a consumable product that contains the toner. Toner is a powdery mixture of plastic resin and iron oxide. The plastic allows it to be melted and fused to the paper, and the iron oxide allows it to be moved around via positive or negative charge. Toner comes in a cartridge, like the one shown in Figure 3.71.

The drum is light sensitive; it can be written to with the laser scanning assembly. The toner cartridge in Figure 3.71 contains the print drum, so every time you change the toner cartridge, you get a new drum. In some laser printers, the drum is a separate part that lasts longer, so you don’t have to change it every time you change the toner.

Primary Corona (Charge Corona) This applies a uniform negative charge (around –600V) to the drum at the beginning of the printing cycle.

Laser Scanning Assembly This uses a laser beam to neutralize the strong negative charge on the drum in certain areas, so toner will stick to the drum in those areas. The laser scanning assembly uses a set of rotating and fixed mirrors to direct the beam, as shown in Figure 3.72.

Paper Transport Assembly (Transfer Belt, Transfer Rollers) This moves the paper through the printer. The paper transport assembly consists of a motor and several rubberized rollers and transfer belts. These rollers are operated by an electronic stepper motor. See Figure 3.73 for an example.

Pickup Rollers Pickup rollers are rubber wheels that grab the paper and feed it in. When these parts get old, they lose their ability to grip the paper, so they should be checked and changed regularly.

Separate Pads These pads are used to separate sheets in a stack of printing paper. It does this as the paper passes over them by creating friction that separates the paper. These pads are usually 2 to 3 inches wide, and when they start to wear out, they lose their ability to create friction, and you start getting two and three sheets at a time pulled through.

Transfer Corona This applies a uniform positive charge (about +600V) to the paper. When the paper rotates past the drum, the toner is pulled off the drum and onto the paper. Then the paper passes through a static eliminator that removes the positive charge from it (see Figure 3.74). Some printers use a transfer corona wire; others use a transfer corona roller.

High-Voltage Power Supply (HVPS) This delivers the high voltages needed to make the printing process happen. It converts ordinary 120V household AC current into high-DC voltages used to energize the primary and transfer corona wires (discussed later).

DC Power Supply This delivers lower voltages to components in the printer that need much lower voltages than the corona wires do (such as circuit boards, memory, and motors).

Fusing Assembly This melts the plastic resin in the toner so that it adheres to the paper. The fusing assembly contains a halogen heating lamp, a fusing roller made of Teflon-coated aluminum, and a rubberized pressure roller. The lamp heats the fusing roller, and as the paper passes between the two rollers, the pressure roller pushes the paper against the hot fusing roller, melting the toner into the paper (see Figure 3.75).

Duplex Assembly Duplex assemblies were discussed in the section “Duplex” under objective 3.10 earlier in this chapter.

Imaging process: processing, charging, exposing, developing, transferring, fusing, and cleaning

The laser (EP) print process consists of seven steps. Here are the steps in the order you’ll see them on the exam:

Step 1: Processing In this step the data is received by the printer software and the images are rendered for the next step.

Step 2: Charging In the conditioning step (Figure 3.76), a special wire (called a primary corona or charge corona) within the EP toner cartridge (above the photosensitive drum) gets a high voltage from the HVPS. It uses this high voltage to apply a strong, uniform negative charge (around –600VDC) to the surface of the photosensitive drum.

Step 3: Exposing In the writing step of the EP process, the laser is turned on and scans the drum from side to side, flashing on and off according to the bits of information the printer controller sends it as it communicates the individual bits of the image. In each area where the laser touches the photosensitive drum, the drum’s charge is severely reduced from –600VDC to a slight negative charge (around –100VDC). As the drum rotates, a pattern of exposed areas is formed, representing the image to be printed. Figure 3.77 shows this process.

At this point, the controller sends a signal to the pickup roller to feed a piece of paper into the printer, where it stops at the registration rollers.

Step 4: Developing Now that the surface of the drum holds an electrical representation of the image being printed, its discrete electrical charges need to be converted into something that can be transferred to a piece of paper. The EP process’s developing step accomplishes this (Figure 3.78). In this step, toner is transferred to the areas that were exposed in the writing step.

A metallic developing roller or cylinder inside an EP cartridge acquires a –600VDC charge (called a bias voltage) from the HVPS. The toner sticks to this roller because there is a magnet located inside the roller and because of the electrostatic charges between the toner and the developing roller. While the developing roller rotates toward the photosensitive drum, the toner acquires the charge of the roller (–600VDC). When the toner comes between the developing roller and the photosensitive drum, the toner is attracted to the areas that have been exposed by the laser (because these areas have a lesser charge of –100VDC). The toner also is repelled from the unexposed areas (because they’re at the same –600VDC charge and like charges repel). This toner transfer creates a fog of toner between the EP drum and the developing roller.

The photosensitive drum now has toner stuck to it where the laser has written. The photosensitive drum continues to rotate until the developed image is ready to be transferred to paper in the next step.

Step 5: Transferring At this point in the EP process, the developed image is rotating into position. The controller notifies the registration rollers that the paper should be fed through. The registration rollers move the paper underneath the photosensitive drum, and the process of transferring the image can begin with the transferring step.

The controller sends a signal to the corona wire or corona roller (depending on which one the printer has) and tells it to turn on. The corona wire/roller then acquires a strong positive charge (+600VDC) and applies that charge to the paper. The paper, thus charged, pulls the toner from the photosensitive drum at the line of contact between the roller and the paper because the paper and toner have opposite charges. Once the registration rollers move the paper past the corona wire, the static-eliminator strip removes all charge from that line of the paper. Figure 3.79 details this step. If the strip didn’t bleed this charge away, the paper would attract itself to the toner cartridge and cause a paper jam.

The toner is now held in place by weak electrostatic charges and gravity. It won’t stay there, however, unless it’s made permanent, which is the reason for the fusing step.

Step 6: Fusing In the next step, fusing, the toner image is made permanent. The registration rollers push the paper toward the fuser rollers. Once the fuser grabs the paper, the registration rollers push for only a short time more. The fuser is now in control of moving the paper.

As the paper passes through the fuser, the fuser roller melts the polyester resin of the toner, and the rubberized pressure roller presses it permanently into the paper (Figure 3.80). The paper continues on through the fuser and eventually exits the printer.

Step 7: Cleaning In the last part of the laser print process, a rubber blade inside the EP cartridge scrapes any toner left on the drum into a used-toner receptacle inside the EP cartridge, and a fluorescent lamp discharges any remaining charge on the photosensitive drum (remember that the drum, being photosensitive, loses its charge when exposed to light). See Figure 3.81.

The EP cartridge is constantly cleaning the drum. It may take more than one rotation of the photosensitive drum to make an image on the paper. The cleaning step keeps the drum fresh for each use. If you didn’t clean the drum, you would see ghosts of previous pages printed along with your image.

Putting it all together

Figure 3.82 summarizes all the EP process printing steps. First, the printer uses a rubber scraper to clean the photosensitive drum. Then the printer places a uniform –600VDC charge on the photosensitive drum by means of a charge corona. The laser paints an image onto the photosensitive drum, discharging the image areas to a much lower voltage (–100VDC). The developing roller in the toner cartridge has charged (–600VDC) toner stuck to it. As it rolls the toner toward the photosensitive drum, the toner is attracted to (and sticks to) the areas of the photosensitive drum that the laser has discharged. The image is then transferred from the drum to the paper at its line of contact by means of the corona wire (or corona roller) with a +600VDC charge. The static-eliminator strip removes the high, positive charge from the paper, and the paper, now holding the image, moves on. The paper then enters the fuser, where the fuser roller and the pressure roller make the image permanent. The paper exits the printer, and the printer starts printing the next page or returns to its ready state.

Maintenance: Replace toner, apply maintenance kit, calibrate, clean

Just as laser printers are the most complicated of the types (and offer the most capabilities), they also have the most things that can go awry. A thermal fuse is included to keep the system from overheating, and if it becomes faulty, it can prevent the printer from printing. Many high-capacity laser printers also include an ozone filter to prevent the corona’s ozone output from reaching too high a level. On these printers, the filter should be changed as part of regular maintenance.

Other common problems and solutions are as follows:

Paper Jams While paper jams can be caused by numerous problems, two common ones are the paper not feeding correctly and moisture. To correct improper feeds, make sure you set the alignment guides for the paper you are using and verify that the paper is feeding in straight. Keep the paper from getting any moisture before feeding into the printer because moisture often causes pages to stick together and bind. Paper jams can also be caused by using paper that is not approved for the printer—particularly thick cardstock.

Regardless of the cause of a paper jam, you need to always fully clear the printer of any traces of paper (torn or whole) before attempting to print again.

Error Codes Many laser printers include LCDs for interaction with the printer. When error codes appear, refer to the manufacturer’s manuals or website for information on how to interpret the codes and solve the problem causing them.

Out-of-Memory Error While PCs now may need a minimum of 1 GB of RAM to run at a base level, it is not uncommon to find printers that still have only 4 MB or 8 MB of memory. If you are routinely running out of memory on a printer, add more memory if possible, and replace the printer when it is no longer possible to do so.

Lines and Smearing Lines and smearing can be caused by the toner cartridge or the fuser. Try replacing the toner first (and cleaning any that may have spilled). If this does not fix the problem, replace the fuser.

Blank Pages Print Verify that there is toner in the cartridge. If it’s an old cartridge, you can often shake it slightly to free up toner once before replacing. If it’s a new cartridge, make sure the sealing tape has been removed from the cartridge prior to placing it in the printer.

Dark Spots Print The most likely culprit is too much toner. Run blank pages through the printer to clean it.

Garbled Pages Print Make sure you’re using the right printer driver in your application.

Ghosted Images Print Ghosting—repeating text or images on the page—is usually caused by a bad cartridge. There can be damage to the drum or charging roller, and if there is, replacing the cartridge will help with the problem.

No Connectivity If a network printer is not able to receive jobs, the issue may be with the IP address that it has (or, more correctly, does not have). Often the printer will need to be manually assigned an IP address to make sure that it has the same one each time. Read the manufacturer’s documentation for assigning an IP address to the printer and walk through the steps to do so.

Print-Quality Problems See whether your printer has the ability to turn Resolution Enhancement Technology (RET) on and off. This is what allows the printer to use partial-sized dots for images that are rounded. If it’s turned off, turn it back on. If there are small marks or defects in the same spot on every page printed, the most likely culprit is a scratch on the drum.

Replacing Toner Toner represents the consumable within the laser printer. Toner cartridges are used by laser printers to store toner. Use toner that is recommended for your printer. Using bad supplies could ruin your printer and void your warranty. Remove the toner before moving or shipping a printer to avoid spills.

Applying a Maintenance Kit Maintenance kits are marketed by the manufacturer. Each kit varies in contents based on the printer in question but typically consists of a fuser, transfer roller, and feed/separation rollers. A counter on the laser printer often identifies when the maintenance kit is needed, and you can reset the counter after applying the new kit.

Calibration With laser printers and inkjets, there is often a need to calibrate. Calibration is the process by which the result produced matches what was created. All the hardware, including the monitor, scanner, and printer, need to match on color, margins, and so forth.

The calibration process is different for each manufacturer but is usually similar to the following:

1. During installation of the software, you are asked (by the installation wizard) if you want to calibrate now (say Yes).
2. The printer prints multiple sets of numbered lines. Each set of lines represents an alignment instance, and you are asked which set looks the best.
3. You enter the set number and click OK. In some cases, the alignment ends here. In other cases, the alignment page is reprinted to verify that the settings are correct, and you are given a chance to change.
4. You exit the alignment routine.

Cleaning It is important to keep the printer and the area around it clean. Each time you replace the toner or perform any maintenance, be sure to clean the debris.

Ink cartridge, print head, roller, feeder, duplexing assembly, carriage, and belt

Components of an inkjet printer are covered in the following sections.

Calibrate

Calibrating an inkjet printer is the process of ensuring that there is proper alignment of the cartridges to one another and to the paper so that high quality is maintained. When a printer gets out of calibration, the print quality will decline. When a new cartridge is loaded, the printer will usually perform a calibration, but you may need to do this manually from time to time, especially on printers that are not used often enough to require a cartridge change as often as a calibration may be required.

On an inkjet printer, calibration is more commonly known as head alignment. The printer will automatically try to align ink cartridges each time they are replaced (or installed). If you want to make sure they are in the right place, most printers allow you to print an alignment page from the maintenance menu.

If characters are not properly formed or are appearing as straight lines along the margin (usually the left), you can use the maintenance menu settings to align the ink cartridges.

Maintenance: Clean heads, replace cartridges, calibrate, clear jams

While inkjet printers use a different technology to print, they require many of the same maintenance procedures. These are discussed briefly in this section.

Clean Heads Two maintenance tasks apply to the print heads. If your colors don’t look the same or your blacks are getting a bronze look, you need to clean the nozzles. This can be done with the head cleaning cycle, which will clear out the nozzles. The second task is head alignment. If you see white repeating lines or a grid-like pattern in the printing, the head is misaligned. While some newer printers have an automatic alignment and cleaning function, you may need to do this manually using the printer documentation.

Replace Cartridges When ink runs low (and most printers will alert you before you run out), you must remove the old cartridge and replace it with a new one. The procedure is as follows:

1. Open the printer cover and locate the button that is used to place the cartridge in the replacement position.
2. Open the cover that may be over the cartridge.
3. Grasp and remove the empty cartridge.
4. Take the new cartridge out of its packaging.
5. Place the new cartridge in the empty position left by the old cartridge. It should click into place.
6. Replace the cartridge cover.
7. Use the same button you used to place the cartridge into the replacement positon to move it back to the home position.

Calibration Calibration is a task usually performed by accessing the properties of the printer and looking for the calibration function either on the General tab or on the Advanced tab. Just select it, and the printer will perform a calibration. It is also useful to know that in most cases a calibration is done whenever you replace one of the cartridges.

Clear Jams While keeping in mind that many paper jams are a result of using poor-quality paper, there will be times you suffer jams with good paper. To clear a jam, do the following:

1. Check the paper tray. If you see a piece protruding from where the paper is picked up, pull it out gently.
2. If there is still a jam, remove the rear access door and look into the printer. If you see any paper stuck inside, pull it out, making sure you get all the pieces out.
3. Check the front door of the printer and see whether any pieces are stuck in that section; if so, gently pull them out.
4. At any point in this process you can select the Resume button, and if you have cleared the jam, the print process will resume.

Feed assembly, heating element

Thermal printers work by using a print head the width of the paper. When it needs to print, the print head heats and cools spots on the print head. The paper below the heated print head turns black in those spots. As the paper moves through the printer, the pattern of blackened spots forms an image on the page of what is being printed.

Another type of thermal printer uses a heat-sensitive ribbon instead of heat-sensitive paper. A thermal print head melts wax-based ink from the ribbon onto the paper. These are called thermal transfer or thermal wax-transfer printers.

Thermal direct printers typically have long lives because they have few moving parts. However, the paper is somewhat expensive, doesn’t last long, and produces poorer-quality images (that tend to fade over time) than most of the other printing technologies.

There are some variations of thermal printing that exist. They’re all high-end color graphics printers designed for specialty professional usage. Here are four popular ones:

Thermal Wax Transfer This is a color, nonimpact printer that uses a solid wax. A heater melts the wax and then sprays it onto the page, somewhat like an inkjet. The quality is very high, but so is the price.

Dye Sublimation This is another color, nonimpact line printer. This one converts a solid ink into a gas that is then applied to the paper. Color is applied in a continuous tone, rather than individual dots, and the colors are applied one at a time. The ink comes on film rolls. The paper is expensive, as is the ink. Print speeds are low. The quality is extremely high.

Feed Assembly Feed assemblies, commonly called feeders, are available to allow you to feed in the media you are printing on (paper, cards, and so on). Some feeders allow you to switch between multiple feeds, which is helpful if you need to alternate printing on different types of stock.

Heating Element The heating element for a thermal printer is what generates the heat and does the actual printing. It is often the most expensive component.

Special thermal paper

To print with a thermal printer, you need to use heat-sensitive paper designed for the thermal printer as opposed to paper for any other type of printer. Rolls of thermal paper are available in a variety of sizes and colors.

Maintenance: Replace paper, clean heating element, remove debris

The amount of maintenance required on a thermal printer pales in comparison to laser since there are no moving parts to speak of. The following sections look at the key items to be aware of related to thermal printers as you study for the exam.

Replace Paper Replace the thermal paper as it is needed; be sure to keep the feed area clean of paper slivers and other debris.

Clean Heating Element Before even looking at a heating element, always unplug the printer and make certain it is cool. Thermal printer cleaning cards, cleaning pens, and kits are available and recommended for cleaning.

Remove Debris Keep the printer free of dust and debris. Any particulates that get into the printer can interfere with the paper feeding properly or can affect the print quality. Use compressed air or a computer vacuum to remove any debris.

Print head, ribbon, tractor feed

Key elements of an impact printer are discussed in the sections that follow.

Print Head The pins in the print head are wrapped with coils of wire to create a solenoid and are held in the rest position by a combination of a small magnet and a spring. To trigger a particular pin, the printer controller sends a signal to the print head, which energizes the wires around the appropriate print wire. This 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.

Ribbon The ribbon is like that on an old typewriter. Most impact printers have an option to adjust how close the print head rests from the ribbon. So if your printing is too light, you may be able to adjust the print head closer to the ribbon. If it’s too dark or you get smeared printing, you may be able to move the print head back.

Tractor Feed The tractor feed unit feeds in the continuous feed paper. This paper has holes running down both edges.

Impact paper

An impact printer uses continuous feed paper fed to it by the tractor feed unit.

Maintenance: Replace ribbon, replace print head, replace paper

A dot-matrix print head reaches high temperatures, and care must be taken to avoid a user or technician touching it and getting burned. Most dot-matrix printers include a temperature sensor to tell whether the print head is getting too hot. The sensor interrupts printing to let the print head cool down and then allows printing to start again. If this sensor becomes faulty, it can cause the printer to print a few lines, stop for a while, print more, stop, and so on. The following sections look at the key items to be aware of related to impact printers as you study for the exam.

Replace ribbon. A common culprit with poor printing is the ribbon. A tight ribbon, or one that isn’t advancing properly, will cause smudges or overly light printout. To solve this problem, replace the ribbon.

Replace print head. The print head should never be lubricated, but you can clean off debris with a cotton swab and denatured alcohol. Print pins missing from the print head will cause incomplete images or characters or white lines running through the text. This can be remedied by replacing the print head.

If the print head isn’t at fault, make certain it’s close enough to the platen to make the right image. The print head can be moved closer and farther from the platen (the surface on which typing occurs) depending on the thickness of the paper and other considerations.

Replace paper. Preventive maintenance includes not only keeping the print head dry and clean but also vacuuming paper shreds from inside the machine. This should be done more often if needed but always when you replace the paper.

Print to file

Print to file is quite an old concept by now but still available as an option when printing. When you do this, the information that would normally be sent to the printer is saved, usually as a .prn file. It is a way to avoid the printing process from within an application (which may be time-consuming or inconvenient) and print it (convert it) once and then save the file so that whenever you need a copy, you can simply send that to the printer.

Print to PDF

If you can print to file, you can print to PDF. In applications that support this feature, it will be an option presented when you select to print. When you select this option, it produces an Adobe PDF instead of a printout. It is a convenient format because you can still print the document later, search it, and send it; and when you do send it, you can be certain that the way the document appears to you will be the way it does to the recipient, regardless of the device type on which they are viewing it.

Print to XPS

An XPS document is a standardized open format and is Microsoft’s answer to the PDF. It is always offered as a printer type in Windows. It will be called a Microsoft XPS Document Writer and will appear with other printers in the printer’s folder, as shown in Figure 3.69 earlier. When your file is converted, it will appear with an .opxs file extension (Open XPS). While Microsoft encourages the use of these documents and of the default XPS device and offers more support for it then for PDF, the document type is not as widely supported elsewhere as the PDF.

Print to image

Finally, printing to an image is somewhat like scanning because it creates an image of the document. This typically requires a third-party application. Many of the applications that will create a PDF, such as Nitro PDF Writer, will also allow for you to convert those formats to a .jpg file.

Plastic filament

3D printers use rolls of special plastic filament as the material source. This filament comes in various colors and is shown in Figure 3.84 with objects created from the filament.