A+ Essentials Study Guide - Laptops Part 1

2.1 Identify the fundamental principles of using laptops and portable devices Part 1

> Identify names, purposes and characteristics of laptop-specific:

Form factors such as memory and hard drives

Notebook Memory

Most laptops use different memory modules than desktops for their random access memory (RAM), for instance, SO-DIMM in lieu of the larger DIMMs. SO-DIMM's are smaller and thus save space.

Memory types used in laptops include:

• Small Outline Dual Inline Memory Module (SODIMM)
• Dual Data Rate Synchronous RAM (DDR SDRAM)
• Single data rate Synchronous RAM (SDRAM)
• Proprietary memory modules

SODIMM's used in Laptops is a smaller version of the DIMM found on desktop PC'c. They have a notch in the bottom of the circuit board, which is offset from the middle, which makes inserting it easier to line up.200-pin SODIMMs are used to provide DDR SDRAM memory for laptop computers.

Each 200-pin SODIMM provides a 64-bit data path, so they are installed alone in 64-bit systems. 200-pin SODIMMs are available in PC2100, PC2700 and PC3200.

The number of black chips on a 200-pin SODIMM may vary, but they always have 100 pins on the front and 100 pins on the back for a total of 200. 200-pin SODIMMs are approximately 2.6" long and 1" high, and the heights may vary.

Laptop Hard Drives

Like a desktop, a laptop has an internal hard disk drive, which stores the operating system, applications and data files. However, laptops generally have less disk space than desktops. A laptop hard drive is also physically smaller 2.5 inch compared to 3.5 inch for a desktop. In addition, most laptop hard drives spin more slowly than desktop hard drives, reducing both heat and power consumption.

Desktop computers have multiple bays for installing additional drives, such as CD and DVD ROM drives. However, space in a laptop is in much shorter supply. Many laptops use a modular design, allowing a variety of drives to fit in the same bay.

These drives come in three different designations:

• Hot swappable - The computer can stay on while changing the drive.
• Warm swappable - The computer can stay on while changing the drive, but the corresponding bus (the path the drive uses to send data to the CPU) must be inactive.
• Cold swappable - The computer must be off during the swap.

In some cases, these drive bays are not just limited to drives but will also accept extra batteries.

> Peripherals (e.g. docking station, port replicator and media / accessory bay)

Docking Station

A docking station is a part of a portable computer that remains on a desk, containing hardware that is not needed when on the road, while a smaller section detaches to provide a lighter laptop. Docking stations are often used to outfit a light-weight ultraportable so that it is more of a desktop replacement, for use at home. Docking stations provide for extra connections like slots for expansion cards but a port replicator does not. Extra devices that a docking station can support include: hard drive bays, optical drive bays, keyboard/mouse connectors (PS/2 ports), additional USB ports, PC Card slots, external display connectors, and a variety of other devices that are deemed to be unnecessary on a laptop and/or add weight and decrease portabilty.

Docking Station

Docking or undocking of portable computers can be done either hot or cold. In a cold dock or undock, the computer is shut down before it is inserted into or removed from the docking station. In a hot dock or undock, the computer is running, with or without programs and documents open, when it is inserted into or removed from the docking station. Computer manufacturers can design the docking stations and BIOS of their mobile computers in different ways resulting in different docking and undocking behaviors.

Recent docking station designs use the laptop screen rather than an external monitor as the primary screen. This type of docking station is also referred to by some as a laptop stand. Most examples offer a connection to peripherals such as keyboards and mice and networks via an internal USB hub. This type of dock was first introduced in 2002 as the Oysterdock referencing the way the dock clamps around the laptop when it is docked. It also allows users to place their laptop screen in an ergonomically correct position.

Port Replicator

A port replicator is a convenient way to attach external devices such as a monitor, a full-size keyboard, or an AC power adapter. Although devices can be attached directly to the connectors on the computer rear panel, the port replicator lets you make all of those connections in one step. The port replicator also gives you access to additional connectors not found on the laptop rear panel.

When a notebook is docked, the docking station / port replicator must be connected to AC power to function properly.

Port Replicator

Rear view of a Gateway port replicator.