PC Card - Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/PC_Card

PC Card From Wikipedia, the free encyclopedia

In computing, PC Card (originally PCMCIA, or PCMCIA Card) is the form factor of a peripheral interface designed for laptop computers. The PC Card standard (as well as its successor ExpressCard) were defined and developed by a group of industry-leading companies called the Personal Computer Memory Card International Association (PCMCIA). The United States computer industry created the Personal Computer Memory Card International Association to challenge the Japanese JEIDA memory card devices by offering a competing standard for memory-expansion cards. In 1991 the two standards merged as JEIDA 4.1 or PCMCIA 2.0 (PC Card). PC Card was originally designed for computer memory expansion, but the existence of a usable general standard for notebook peripherals led to many kinds of devices being made available in this form. Typical devices included network cards, modems, and hard disks. The cards were also use in early digital SLR cameras, such as the Kodak DCS 300 series. The original use, as memory expansion, is no longer common. Many notebooks in the 1990s came with two type-II slots with no barrier in between (allowing installation of two type-II cards or one, double-sized, type-III card). With the removal of legacy ports, most contemporary notebooks only feature a single type-II card slot.

Contents 1 Name 2 Card types 2.1 Type I 2.2 Type II 2.3 Type III 2.4 Type IV 3 Card Information Structure 4 Card Manufactures 5 CardBus 6 CardBay 7 Descendants and variants 8 Technological obsolescence 9 See also 10 References 11 External links

Two PC Card devices: Xircom RealPort (top) type III and 3Com (bottom) type II.

Name PCMCIA stands for Personal Computer Memory Card International Association, the group of industry-leading companies that defines and develops the standard. While this acronym did clearly describe the original intentions of the organization's standard, it was difficult to say and remember, and was sometimes jokingly referred to as "People Can't Memorize Computer Industry Acronyms".[1] To aid in the widespread marketing and branding of the standard, and to account for the standard's

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PC Card - Wikipedia, the free encyclopedia

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widening scope (beyond just memory cards), the association acquired the rights to the simpler term "PC Card" from IBM, and began using it, rather than "PCMCIA", from version 2 of the specification onwards.

Card types All PC Card devices use an identical 68 pin dual row connecting interface. All are 85.6 mm long and 54.0 mm wide. This is the same size as a credit card. The form factor is also used by the Common Interface form of Conditional Access Modules for DVB broadcasts. 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. The original standard was built around an 'enhanced' 16-bit ISA bus platform.

Type I Cards designed to the original specification (version 1.x) are type I and feature a 16-bit interface. They are 3.3 mm thick. Type-I PC Card devices are typically used for memory devices such as RAM, flash memory, OTP, and SRAM cards.

Type II Type-II PC Card devices feature a 16- or 32-bit interface. They are 5.0 mm thick. Type-II cards introduced I/O support, allowing devices to attach an array of peripherals or to provide connectors/slots to interfaces for which the host computer 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.

Type III Type-III PC Card devices are 16-bit or 32-bit. 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).

Type IV Type-IV cards, introduced by Toshiba, have not been officially standardized or sanctioned by the PCMCIA. These cards are 16 mm thick.

Card Information Structure The Card Information Structure (CIS) is information stored on a PC card that contains information about the formatting and organisation of the data on the card.[2] The CIS also contains information about: The type of card

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Supported power supply options Supported power saving features The manufacturer Model number and so on. When a card is unrecognised it is frequently because the CIS information is either lost or damaged.

Card Manufactures NexAira inc. (http://www.nexaira.com) produces Mobile Broadband Wireless Cards, including Type II PC Cards, 3G EV-DO Rev A USB Modems, and 3G 7.2 ExpressCard - HSDPA. NexAira also produces the NexConnect Cellular Router that works with 3G backhaul technologies such as CDMA or GSM and a traditional wired backhaul such as ADSL or Cable. Capable of handling continuous computing, allowing multiple users to share a Wi-Fi Hot Spot, supports VPN pass through, VOIP and media content storage.

CardBus CardBus are PCMCIA 5.0 or later (JEIDA 4.2 or later) 32-bit PCMCIA devices, introduced in 1995 and present in laptops from late 1997 onward. CardBus 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. The notch on the left hand front of the device is slightly shallower on a CardBus device, so a 32-bit device cannot be plugged into a slot that can only accept 16-bit devices. Most new slots are compatible with both CardBus and the original 16-bit PC Card devices.

Two Xircom RealPort Ethernet/56k modem cards. Top one is CardBus, and the bottom is the 5 volt PCMCIA version. Note the slightly different notch.

The speed of CardBus interfaces in 32 bit burst mode depends on the transfer type; in byte mode it is 33 MB/s, in Word mode it is 66 MB/s, and in DWord mode it is 132 MB/s.

CardBay CardBay is a variant added to the PCMCIA specification in 2001. This was intended to add some forward compatibility with USB and IEEE 1394, but was not universally adopted and only some notebooks support CardBay features in their PC Card controllers.

Descendants and variants The interface has spawned a generation of flash memory cards that set out to improve on the size and features of Type I cards: CompactFlash, MiniCard and SmartMedia. For example, the PC Card electrical specification is also used for CompactFlash, so a PC Card CompactFlash adapter need only be a socket adapter.

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PC Card - Wikipedia, the free encyclopedia

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ExpressCard is a later specification from the PCMCIA, intended as a replacement for PC Card, built around the PCI Express and USB 2.0 standards. The PC Card standard is closed to further development and PCMCIA strongly encourages future product designs to utilize the ExpressCard interface. As of 2007, the majority of laptops now ship with only ExpressCard slots or neither slot type (leaving expansion to USB and Firewire only), though the Lenovo Thinkpad T60 and Z60m, among other models, currently ships with both CardBus and ExpressCard slots. ExpressCard and CardBus sockets are physically and electrically incompatible. Therefore, a simple mechanical adapter between the two formats is infeasible.[3] However, Duel Systems has developed a general-purpose adapter that electrically and physically adapts PC Card and CardBus devices to operate in ExpressCard slots [1] (http://www.duel-systemsadapters.com/?productid=DP-0001) . Duel Systems has also developed a forwards-compatible ExpressCard-to-CardBus adapter, though it is limited to USB-based ExpressCard devices [2] (http://www.duel-systemsadapters.com/?productid=DP-0002) .

Technological obsolescence For the most part Firewire and USB devices have replaced this interface. Although this interface is perfect for high density flash memory and Bluetooth and other kinds of wireless modems -- the generic USB and Firewire interfaces that accomplish the same functionalities are more than adequate for the same task.

See also USB for mobile modems Zoomed video port ExpressCard List of device bandwidths

References 1. ^ Clark, Scott H.; Norton, Peter (2002). Peter Norton's new inside the PC. Indianapolis: SAMS, 33. ISBN 0-672-32289-7. 2. ^ Linux PCMCIA Programmer's Guide (http://pcmcia-cs.sourceforge.net/ftp/doc/PCMCIA-PROG.html) 3. ^ PCMCIA Frequently Asked Questions (http://www.pcmcia.org/faq.htm#expresscard) .

External links Related and official sites PCMCIA official site (http://www.pcmcia.org) PC Card overview (http://www.pcmcia.org/pccard.htm) PC Card FAQ (http://www.pcmcia.org/faq.htm) PC Card standard (http://www.pcmcia.org/pccard.htm#stan) CardBus white paper (http://www.pcmcia.org/papers/new_bus.htm) Linux PCMCIA Information Page (kernel 2.4 and earlier) (http://pcmcia-cs.sf.net/) Linux Kernel 2.6 PCMCIA (http://kernel.org/pub/linux/utils/kernel/pcmcia/pcmcia.html) PCMCIA/CardBus Linux Status Survey (http://tuxmobil.org/pcmcia_linux.html) PCMCIA pinout (http://pinouts.ws/pcmcia-pinout.html) PCMCIA (PC Card) pinout and signals (http://pinouts.ru/Slots/PcCard_pinout.shtml) Simple FAQ on PCMCIA & PC Card (http://www.sycard.com/pcard_qa.html)

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Retrieved from "http://en.wikipedia.org/wiki/PC_Card" Categories: Computer buses | Standards organizations | Motherboard Hidden categories: Articles needing additional references from June 2007 | All articles with unsourced statements | Articles with unsourced statements since July 2007 This page was last modified on 3 April 2008, at 23:42. All text is available under the terms of the GNU Free Documentation License. (See Copyrights for details.) Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a U.S. registered 501(c)(3) tax-deductible nonprofit charity.

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