PC card
Encyclopedia
In computing
, PC Card (originally PCMCIA Card) is the form factor of a peripheral interface designed for laptop
computers. The PC Card standard (as well as its successor ExpressCard
) was defined and developed by the Personal Computer Memory Card International Association (PCMCIA) which itself was created by a number of computer industry companies in the United States to offer a standard for memory-expansion cards that would compete with the JEIDA memory card
standard developed in Japan. It was invented by Jacob D. Holm in 1986, and in 1991 the two standards merged as JEIDA 4.1 or PCMCIA 2.0 (PC Card).
PC Card was originally designed for computer storage
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 card
s, modem
s, and hard disk
s. The cards were also used in early digital SLR cameras, such as the Kodak DCS 300 series
. The original use, as storage expansion, is no longer common.
Many notebooks in the 1990s had two adjacent type-II slots, which allowed installation of two type-II cards or one, double-thickness, type-III card. The PC card port has been superseded by the faster ExpressCard
interface, but some modern portable computers still use them.
. This was the name of the standard from version 2 of the specification onwards. These cards are used for wireless networks
, modem
s, and other functions in notebook PCs.
The PCMCIA was dissolved in 2009, and all of its activities are now managed by the USB Implementer's Forum
, according to the PCMCIA website.
Another name for PCMCIA or PC Card is CardBus, the 32-bit version of the PCMCIA PC Card standard. In addition to supporting a wider bus (32 bits instead of 16 bits), CardBus also supports bus mastering and operation speeds up to 33 MHz.
. The form factor
is also used by the Common Interface
form of Conditional Access Modules for DVB broadcasts, and by Panasonic for their professional "P2" video acquisition memory cards.
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 prevent them from being inserted fully 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.
, flash memory
, OTP
, and SRAM
cards.
: a short cable that adapts from the card's miniature connector to an external full-size connector. Some cards instead have a lump on the end with the connectors. This is more robust and convenient than a separate adapter but can block the other slot where slots are present in a pair. Some Type II cards, most notably network interface and modem cards have a retractable jack, when pushed in it will pop out, allowing insertion of a cable from above. When use of the card is no longer needed, the jack can be pushed back into the card and lock in place, protecting it from damage. Most network cards have their jack on one side, while most modems have their jack on the other side, allowing the use of both at the same time as they do not interfere with each other. Wireless Type II cards often had a plastic shroud jutting out from the end of the card, inside which the antennas were housed.
, have not been officially standardized or sanctioned by the PCMCIA. These cards are 16 mm thick.
storage" interface mode.
The CIS also contains information about:
When a card is unrecognized it is frequently because the CIS information is either lost or damaged.
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 supports bus mastering
, which allows a controller on the bus to talk to other devices or memory without going through the CPU
. Many chipsets, such as those that support Wi-Fi
, are available for both PCI and CardBus.
The notch on the left hand front of the device is slightly shallower on a CardBus device so, by design, a 32-bit device cannot be plugged into earlier equipment supporting only 16-bit devices. Most new slots accept both CardBus and the original 16-bit PC Card devices. CardBus cards can be distinguished from older cards by the presence of a gold band with eight small studs on the top of the card next to the pin sockets.
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 66 MB/s, and in dword mode 132 MB/s.
initiative.
, MiniCard
, P2 Card
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.
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), for a while some laptops were shipped with both CardBus and ExpressCard slots such as the Lenovo Thinkpad
T60 and Z60m
, the current trend (August 2011) is to ship laptops with only USB expansion even fullsize laptops (such as the HP G56-100SA 15.6" Laptop) do not have internal expansion slots.
ExpressCard and CardBus sockets are physically and electrically incompatible. Therefore, a simple mechanical adapter between the two formats is infeasible. However, several companies now produce ExpressCard-to-CardBus and Cardbus-to-ExpressCard adapters that use a secondary slot to allow older cards to work with newer PCs and vice versa.
Adapters for PC Cards to Personal Computer ISA slots were available as well as currently there are PC Card (Cardbus) adapters for PCI slots. Wireless (802.11) PCMCIA cards were sometimes sold with PC Card to PCI adapter for desktop use, such as Linksys WPC11 wireless pccard and WDT11 pccard to pci adapter.
which replaces the PC Card, contains a PCIe 1x and a USB 2.0 interface. Cardbus devices can be plugged into an ExpressCard adaptor having a PCI-to-PCI Bridge.
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
, PC Card (originally PCMCIA Card) is the form factor of a peripheral interface designed for laptop
Laptop
A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...
computers. The PC Card standard (as well as its successor ExpressCard
ExpressCard
ExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
) was defined and developed by the Personal Computer Memory Card International Association (PCMCIA) which itself was created by a number of computer industry companies in the United States to offer a standard for memory-expansion cards that would compete with the JEIDA memory card
JEIDA memory card
The JEIDA memory card standard was a popular memory card standard at the beginning of memory cards appearing on portable computers. JEIDA cards could be used to expand system memory or as a solid-state storage drive...
standard developed in Japan. It was invented by Jacob D. Holm in 1986, and in 1991 the two standards merged as JEIDA 4.1 or PCMCIA 2.0 (PC Card).
PC Card was originally designed for computer storage
Computer storage
Computer data storage, often called storage or memory, refers to computer components and recording media that retain digital data. Data storage is one of the core functions and fundamental components of computers....
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 card
Network card
A network interface controller is a computer hardware component that connects a computer to a computer network....
s, modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
s, and hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
s. The cards were also used in early digital SLR cameras, such as the Kodak DCS 300 series
Kodak DCS 300 series
The Kodak DCS 300 series comprised two cameras, the DCS 315 and DCS 330. They were professional-level digital SLR cameras built by Eastman Kodak's Kodak Professional Imaging Solutions division. They were based on the Nikon Pronea 600i APS SLR cameram and were aimed at a lower price point than other...
. The original use, as storage expansion, is no longer common.
Many notebooks in the 1990s had two adjacent type-II slots, which allowed installation of two type-II cards or one, double-thickness, type-III card. The PC card port has been superseded by the faster ExpressCard
ExpressCard
ExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
interface, but some modern portable computers still use them.
Summary
- Pc Card = PCMCIA Card (older name) = 16bit or 32bit.
- Pc Card 32bit version = Cardbus (alternative name).
- 16bit vs 32bit: 32bit includes DMA or Bus Mastering, 16bit does not.
- Type I-III:
- Type I: 16bit. Formfactor thickness 3.3 mm.
- Type II: 16bit or 32bit. Formfactor thickness 5.0 mm.
- Type III: 16bit or 32bit. Formfactor thickness 10.5 mm.
- Pc Card was superseded by ExpressCardExpressCardExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
in 2003.
- Pc Card was superseded by ExpressCard
Name
PCMCIA stands for Personal Computer Memory Card International Association, the group of companies that defined the standard. This acronym was difficult to say and remember, and was sometimes jokingly referred to as "People Can't Memorize Computer Industry Acronyms". To recognize increased scope beyond memory, and to aid in marketing, the association acquired the rights to the simpler term "PC Card" from IBMIBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
. This was the name of the standard from version 2 of the specification onwards. These cards are used for wireless networks
Wireless LAN
A wireless local area network links two or more devices using some wireless distribution method , and usually providing a connection through an access point to the wider internet. This gives users the mobility to move around within a local coverage area and still be connected to the network...
, modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
s, and other functions in notebook PCs.
The PCMCIA was dissolved in 2009, and all of its activities are now managed by the USB Implementer's Forum
USB Implementers Forum
The USB Implementers Forum is a non-profit organisation to promote and support the Universal Serial Bus. Its main activities are the promotion and marketing of USB, Wireless USB, USB On-The-Go, and the maintenance of the specifications, as well as a compliance program.It was formed in 1995 by the...
, according to the PCMCIA website.
Another name for PCMCIA or PC Card is CardBus, the 32-bit version of the PCMCIA PC Card standard. In addition to supporting a wider bus (32 bits instead of 16 bits), CardBus also supports bus mastering and operation speeds up to 33 MHz.
Card types
All PC Card devices use a similar sized package which is 85.6 mm long and 54.0 mm wide. This is the same size as a credit cardCredit card
A credit card is a small plastic card issued to users as a system of payment. It allows its holder to buy goods and services based on the holder's promise to pay for these goods and services...
. The form factor
Form factor
Form factor may refer to:*Form factor or emissivity, the proportion of energy transmitted by that object which can be transferred to another object...
is also used by the Common Interface
Common Interface
In Digital Video Broadcasting, the Common Interface is an extensible digital interconnect found in the digital TV market. It is also known as DVB-CI for Digital Video Broadcast Common Interface....
form of Conditional Access Modules for DVB broadcasts, and by Panasonic for their professional "P2" video acquisition memory cards.
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 prevent them from being inserted fully 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
Industry Standard Architecture
Industry Standard Architecture is a computer bus standard for IBM PC compatible computers introduced with the IBM Personal Computer to support its Intel 8088 microprocessor's 8-bit external data bus and extended to 16 bits for the IBM Personal Computer/AT's Intel 80286 processor...
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 and feature a dual row of 34 holes (68 in total) along a short edge as a connecting interface. Type-I PC Card devices are typically used for memory devices such as RAMRam
-Animals:*Ram, an uncastrated male sheep*Ram cichlid, a species of freshwater fish endemic to Colombia and Venezuela-Military:*Battering ram*Ramming, a military tactic in which one vehicle runs into another...
, flash memory
Flash memory
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...
, OTP
OTP
Technology* One-time programmable, a type of programmable read-only memory in electronics* One-time pad in cryptography* One-time password, an authentication mechanism, usually in computer security...
, and SRAM
Static random access memory
Static random-access memory is a type of semiconductor memory where the word static indicates that, unlike dynamic RAM , it does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit...
cards.
Type II
Type-II and above PC Card devices use two rows of 34 sockets, and 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 dongleDongle
A software protection dongle is a small piece of hardware that plugs into an electrical connector on a computer and serves as an electronic "key" for a piece of software; the program will only run when the dongle is plugged in...
: a short cable that adapts from the card's miniature connector to an external full-size connector. Some cards instead have a lump on the end with the connectors. This is more robust and convenient than a separate adapter but can block the other slot where slots are present in a pair. Some Type II cards, most notably network interface and modem cards have a retractable jack, when pushed in it will pop out, allowing insertion of a cable from above. When use of the card is no longer needed, the jack can be pushed back into the card and lock in place, protecting it from damage. Most network cards have their jack on one side, while most modems have their jack on the other side, allowing the use of both at the same time as they do not interfere with each other. Wireless Type II cards often had a plastic shroud jutting out from the end of the card, inside which the antennas were housed.
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 ToshibaToshiba
is a multinational electronics and electrical equipment corporation headquartered in Tokyo, Japan. It is a diversified manufacturer and marketer of electrical products, spanning information & communications equipment and systems, Internet-based solutions and services, electronic components and...
, have not been officially standardized or sanctioned by the PCMCIA. These cards are 16 mm thick.
Compact Flash
Compact Flash is a smaller dimensioned 50 pin subset of the 68 pin PCCard interface. It has a "memory" mode and an "ATAAT Attachment
Parallel ATA , originally ATA, is an interface standard for the connection of storage devices such as hard disks, solid-state drives, floppy drives, and optical disc drives in computers. The standard is maintained by X3/INCITS committee...
storage" interface mode.
Card information structure
The card information structure (CIS) is information stored on a PC card that contains information about the formatting and organization of the data on the card.The CIS also contains information about:
- The type of card
- Supported power supply options
- Supported power saving features
- The manufacturer
- Model number
- and so on.
When a card is unrecognized it is frequently because the CIS information is either lost or damaged.
CardBus
Peripheral Component Interconnect
Conventional PCI is a computer bus for attaching hardware devices in a computer...
bus in the PC Card form factor. CardBus supports bus mastering
Bus mastering
In computing, bus mastering is a feature supported by many bus architectures that enables a device connected to the bus to initiate transactions...
, which allows a controller on the bus to talk to other devices or memory without going through the CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
. Many chipsets, such as those that support Wi-Fi
Wi-Fi
Wi-Fi or Wifi, is a mechanism for wirelessly connecting electronic devices. A device enabled with Wi-Fi, such as a personal computer, video game console, smartphone, or digital audio player, can connect to the Internet via a wireless network access point. An access point has a range of about 20...
, are available for both PCI and CardBus.
The notch on the left hand front of the device is slightly shallower on a CardBus device so, by design, a 32-bit device cannot be plugged into earlier equipment supporting only 16-bit devices. Most new slots accept both CardBus and the original 16-bit PC Card devices. CardBus cards can be distinguished from older cards by the presence of a gold band with eight small studs on the top of the card next to the pin sockets.
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 66 MB/s, and in dword mode 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 have PC Card controllers with CardBay features. This is an implementation of Microsoft and Intel's Drive BayDrive bay
A drive bay is a standard-sized area for adding hardware to a computer. Most drive bays are fixed to the inside of a case, but some can be removed....
initiative.
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: CompactFlashCompactFlash
CompactFlash is a mass storage device format used in portable electronic devices. Most CompactFlash devices contain flash memory in a standardized enclosure. The format was first specified and produced by SanDisk in 1994...
, MiniCard
Miniature Card
Miniature Card or MiniCard is a flash or SRAM memory card standard first promoted by Intel Corp. in 1995 and backed by Advanced Micro Devices, Fujitsu and Sharp Electronics. Miniature Card Implementers Forum promoted this standard for consumer electronics: PDA/Palmtops, Digital Audio Recorders,...
, P2 Card
P2 (storage media)
P2 is a professional digital recording solid-state memory storage media format introduced by Panasonic in 2004, and especially tailored to electronic news-gathering applications. It features tapeless recording of DV, DVCPRO, DVCPRO25, DVCPRO50, DVCPRO-HD, or AVC-Intra streams on a solid-state...
and SmartMedia
SmartMedia
SmartMedia is a flash memory card standard owned by Toshiba, with capacities ranging from 2 MB to 128 MB. SmartMedia memory cards are no longer manufactured.- History :...
. For example, the PC Card electrical specification is also used for CompactFlash
CompactFlash
CompactFlash is a mass storage device format used in portable electronic devices. Most CompactFlash devices contain flash memory in a standardized enclosure. The format was first specified and produced by SanDisk in 1994...
, so a PC Card CompactFlash adapter need only be a socket
Socket
Socket may refer to:In mechanics:* Socket wrench, a type of wrench that uses separate, removable sockets to fit different sizes of nuts and bolts...
adapter.
ExpressCard
ExpressCard
ExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
is a later specification from the PCMCIA, intended as a replacement for PC Card, built around the PCI Express
PCI Express
PCI Express , officially abbreviated as PCIe, is a computer expansion card standard designed to replace the older PCI, PCI-X, and AGP bus standards...
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), for a while some laptops were shipped with both CardBus and ExpressCard slots such as the Lenovo Thinkpad
ThinkPad
ThinkPad is line of laptop computers originally sold by IBM but now produced by Lenovo. They are known for their boxy black design, which was modeled after a traditional Japanese lunchbox...
T60 and Z60m
Thinkpad Z60m
ThinkPad Z60m is the second model in the Lenovo ThinkPad Z series which, as of May 2006, consists of the Z60t and Z60m. These models are the first ThinkPads to feature a Widescreen aspect ratio. All Z60m devices have integrated WiFi connectivity, a Shock Mounted hard disk drive, a Magnesium...
, the current trend (August 2011) is to ship laptops with only USB expansion even fullsize laptops (such as the HP G56-100SA 15.6" Laptop) do not have internal expansion slots.
ExpressCard and CardBus sockets are physically and electrically incompatible. Therefore, a simple mechanical adapter between the two formats is infeasible. However, several companies now produce ExpressCard-to-CardBus and Cardbus-to-ExpressCard adapters that use a secondary slot to allow older cards to work with newer PCs and vice versa.
Adapters for PC Cards to Personal Computer ISA slots were available as well as currently there are PC Card (Cardbus) adapters for PCI slots. Wireless (802.11) PCMCIA cards were sometimes sold with PC Card to PCI adapter for desktop use, such as Linksys WPC11 wireless pccard and WDT11 pccard to pci adapter.
Technological obsolescence
USB devices are available for almost all functions for which the PC Card interface was originally used. The ExpressCardExpressCard
ExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
which replaces the PC Card, contains a PCIe 1x and a USB 2.0 interface. Cardbus devices can be plugged into an ExpressCard adaptor having a PCI-to-PCI Bridge.
See also
- Conditional access moduleConditional access moduleA conditional access module is an electronic device, usually incorporating a slot for a smart card, which equips an Integrated Digital Television or set-top box with the appropriate hardware facility to view conditional access content that has been encrypted using a conditional access system...
(CAM) - ExpressCardExpressCardExpressCard is an interface to allow peripheral devices to be connected to a computer, usually a laptop computer. Formerly called NEWCARD, the ExpressCard standard specifies the design of slots built into the computer and of cards which can be inserted into ExpressCard slots. The cards contain...
- List of device bandwidths
- USB for mobile modems
- Zoomed video portZoomed video portIn computing, a zoomed video port is a unidirectional video bus allowing a device in a PC card slot to transfer video data directly into a VGA frame buffer, so as to allow laptops to display real-time video...
External links
Related and official sites- Understanding PC Card, PCMCIA, Cardbus, 16-bit, 32-bit.
- PCMCIA official site
- PCMCIA official website (no longer active; archived circa 2008 by the Internet ArchiveInternet ArchiveThe Internet Archive is a non-profit digital library with the stated mission of "universal access to all knowledge". It offers permanent storage and access to collections of digitized materials, including websites, music, moving images, and nearly 3 million public domain books. The Internet Archive...
) - Linux PCMCIA Information Page (kernel 2.4 and earlier)
- Linux Kernel 2.6 PCMCIA
- PCMCIA/CardBus Linux Status Survey
- PCMCIA pinout
- PCMCIA (PC Card) pinout and signals
- Simple FAQ on PCMCIA & PC Card