PC Card
The Personal Computer Memory Card International Association (PCMCIA), founded in 1990 is named after a standard for expansion cards of mobile computers. These cards are known under the name of a PCMCIA card or PC Card.
PCMCIA cards work power saving and support hot-plug, and are therefore changeable during operation. Since all information necessary for automatic driver configuration properties of the map on this in the Card Information Structure (CIS ) are stored, plug and play is also possible.
Development
The first developed by the standardization committee standard (PCMCIA Standard Release 1.0) was focused on the use of PCMCIA cards as memory expansions and was adopted in 1990. In 1991, however, release 2.0 of the specification was released, which now also included protocols for the use of the PCMCIA card as a mobile data memory and for providing communication interfaces. In 1993, finally, the specifications for Release 2.1 have been revised again.
With the introduction of the CardBus standards (PC Card Standard 5.0 ) in 1995 PCMCIA cards were first officially as a PC card (English: PC Card ) designates. Meanwhile, the term PC Card has been enforced only because of the contrast to the acronym PCMCIA simpler marketing.
The PCMCIA standard has thus defines three different sub- standards up to now:
Design
There are three different designs, which measure all 85.6 mm × 54.0 mm, but differ in their thickness:
- Type I ( 3.3 mm ) is used primarily for SRAM or Flash memory cards
- Type II (5.0 mm) is mainly used for modems, network cards, etc. Application
- Type III ( 10.5 mm) was originally required for plug hard drives, but by the progressive miniaturization now seldom used. Therefore, many modern laptops only contain slots for the types I and II
Compatibility
The technique is fully backward compatible. Slots for CardBus cards can therefore also operate 16- bit cards, but not vice versa. Type II slots will also accept Type I, but not type III cards. The voltage required for a card is encoded with a recess at the right side of the face. This prevents that operates 3.3 - volt cards in slots that provide only 5 volts. In slots, which are suitable for 3.3-volt cards, 5 Volt cards can also be plugged, but the card driver will not turn the power on. Some cards can be connected to the 5-volt and 3.3 -volt slots - operate - ie with both voltages.
About a suitable adapter PC Card 16 can be used in a Compact Flash slot. There is currently no possibility of a CardBus card in a conventional PDA to use. But there are a few PDAs with PC card interface. Notebooks from production 1999 are usually equipped with CardBus slots.
For desktop computers exist PCMCIA adapter for the PCI bus. These implement the slot via a plug-in card with a separate PCI - PCMCIA controllers, but in most cases not support hot-plug.
PC Card and the successor ExpressCard
As the successor to the 32- bit PC Card ExpressCard was developed by the PCMCIA, under the code name NEWCARD developed.
This is available as an ExpressCard/34 ( 34 × 75 mm, 5 mm thick) and ExpressCard/54 ( 54 × 75 mm, 5 mm thick), which corresponds to the ExpressCard/34 port, thus this model has an L-shape ).
One ExpressCard/34 is thus almost half smaller than a PCMCIA card of the last generation. The ExpressCard, both the internal USB 2.0 interface or the PCI Express 1x interface to use (= 60 MB / s to 480 Mbit / s) ( 1 lane ). PCI Express works in any direction at 2500 Mbit / s, 250 MB / s because of their relatively 8b10b coding. A PC Card is 32 to 1066 Mbit / s ( 133 MB / s). So that the ExpressCard is about twice or even four times as fast, if a duplex transmission is established.
ExpressCards are not backwards compatible with normal PCMCIA cards. Thus, such cards can not be used readily in conventional CardBus slots or existing PCMCIA or CardBus card into an ExpressCard slot. However, there is a Bridging Adapter ExpressCard to PCMCIA, which allows the.
Similarly, there are - among other things, various wireless providers - adapter to operate data card in ExpressCard/34 and with USB interface in a PC card slot. These include an interface converter. Cards with native PCI Express interface (such as Gigabit Ethernet, eSATA, FireWire) are not supported by these adapters.
Name
The PCMCIA standard is often cited as an example of a deterrent, not self-explanatory names in the computer field. Andrew Grove ( former CEO of Intel) once said: "People Can not Memorize Computer Industry Acronyms " (about: No one can escape the acronyms of the computer industry remember); this quote found its permanent place in the vocabulary of computer specialists.
Examples
Sound Blaster sound card
Used WLAN card ( Thinkpad T20 with disassembled keyboard )
PC card modem with external connection box
View of a network card