A+ Essentials Study Guide - Laptops Part 2

2.1 Identify the fundamental principles of using laptops and portable devices Part 2

> Expansion slots

PCMCIA is the form factor of a peripheral interface designed for laptop computers. It was originally for memory expansion, but the existence of a usable general standard for notebook peripherals led to all manner of devices being made available in this form.

Wireless PC card in slot

Card Types

All PC cards use same connecting interface with 68 pins. All are 85.6 mm long and 54.0 mm wide.

The original standard was defined for both 5 volt and 3.3 volt cards. The 3.3 V cards have a key on the side to protect them from being damaged by being put into a 5 V-only slot. Some cards and some slots operate at both voltages as needed.

Type I: The original specification cards (version 1.x) are Type I and feature a 16 bit interface. Type I cards are used only for memory expansion. They had a single row of connector pins and are 3.3 mm thick. They are primarily used for adding RAM to a notebook PC.

Type II: PC cards feature a 16 or 32 bit interface, using two rows of pins. They are 5.0 mm thick. Type II cards introduced I/O support, allowing PC cards to attach an array of peripherals or to provide connectors/slots to interfaces for which the PC/laptop had no built-in support. For example, many modem, network and TV cards use this form factor. Due to their thinness, most type II interface cards feature miniature interface connectors on the card which are used together with a dongle; a short cable that adapts from the card's miniature connector to an external full-size connector.

The Type III: PC cards are 16 or 32 bit, using two rows of pins. These cards are 10.5 mm thick, allowing them to accommodate devices with components that would not fit type I or type II height. Examples are hard disk drive cards, and interface cards with full-size connectors that do not require dongles (as is commonly required with type II interface cards).

CardBus and ExpressCard

CardBus: are PCMCIA 5.0 or later 32-bit PCMCIA cards, and is effectively a 32-bit, 33 MHz PCI bus in the PC card form factor. CardBus includes bus mastering, which allows a controller on the bus to talk to other devices or memory without going through the CPU. Many chipsets are available for both PCI and CardBus, such as those that support Wi-Fi. ExpressCard: Is a hardware standard replacing CardBus PC cards, both developed by the PCMCIA, which strongly encourages future product designs to utilize the ExpressCard interface. However, many notebook computers as of late 2006 still ship with PC card capabilities, while most newer models are shipping with only ExpressCard slots. These cards are hot-pluggable and the ExpressCard standard uses lower voltages, 1.5V and 3.3V and thus less power than the previous CardBus slots which use 3.3V and 5.0V. ExpressCard supports two form factors, ExpressCard 34 (34 mm wide) and ExpressCard 54 (54 mm wide, in an L-shape) — the connector is the same width (34 mm) on both. Standard cards are 75 mm long (10.6 mm shorter than CardBus) and 5 mm thick, but may be thicker on sections that extend outside the standard form factor — for antennas, sockets, etc. The 34 mm form factor cards fit into both 34 mm and 54 mm card slots via a diagonal guide in the rear of the 54 mm slot that guides the card to the connector. The 54 mm card will only fit in a 54 mm slot.

The major benefit of ExpressCard technology over the CardBus PC card is a big increase in bandwidth, afforded by the fact that the ExpressCard has a direct connection to the system bus over a PCI Express x1 lane or USB 2.0, whereas CardBus utilizes an interface controller that only interfaces with PCI. The ExpressCard has a maximum throughput of 2.5 Gbit/s through PCI Express or 480 Mbit/s through USB 2.0 dedicated for each slot, versus CardBus's shared 1066 Mbit/s bandwidth. The host device supports both PCI Express and USB 2.0 connectivity through the ExpressCard slot. For more info go to Personal Computer Memory Card International Association

> Ports (e.g. mini PCI slot)

Mini PCI slot: is a 32bit, 33MHz PCI slot. Mini PCI is a standard bus for attaching peripheral devices to a computer motherboard and is an adaptation of the Peripheral Component Interconnect (PCI) bus.

There are three card form-factors: Type I, Type II, and Type III cards. The card connector used for each type include: Type I and II use a 100-pin stacking connector, while Type III uses a 124-pin edge connector, i.e. connector for Type I and II differ from Type III, which supports a card edge (like SO-DIMM). The additional 24 pins provide the extra signals required to route I/O back through the system connector (Audio, AC-Link, LAN, Phone-Line interface). Type II cards have an RJ11 and RJ45 mounted connectors. These cards must be located at the edge of the computer or docking station so that the RJ11 and RJ45 ports can be mounted for external access.

As it is functionally equivalent to PCI version 2.2, it is a 32-bit, 33 MHz bus with powered connections (3.3 V only) and support for bus mastering and DMA. Mini PCI cards supports CLKRUN# PCI signal used for start and stop the PCI clock for power management purposes. The standard size for Mini PCI cards is approximately 1/4 of their full-sized counterparts. Given that there is no external access to the card in the same manner that there is for desktop PCI cards, Mini PCI cards are generally limited in the functions they may perform. Mini PCI cards have a 2W maximum power consumption, which also limits the functionality that can be implemented in this form factor.

Many Mini PCI devices are available today: WiFi, modems, sound cards, SCSI, IDE/ATA and SATA controllers. And because Mini PCI and PCI are cousins, you can use regular PCI cards with your Mini PCI-equipped hardware and vice-versa, using Mini PCI-to-PCI and PCI-to-Mini PCI converters.

PCI Express Mini Card is a replacement for the Mini PCI form factor based on PCI Express. It is developed by the PCI-SIG. The host device supports both PCI Express and USB 2.0 connectivity. PCI Express Mini Cards are 30 x 56 mm. There is a 52 pin edge connector. A half-length card is also specified 30 x 31.9 mm.