History and Description of PCMCIA, CardBus & Zoom Video

1. What is PCMCIA?
2. Types of Cards
3. Short History of PCMCIA
4. CardBus
5. Zoom Video
6. CardBus and Zoom Video

1. What is PCMCIA?

   PCMCIA stands for Personal Computer Memory Card International Association (PCMCIA). This is the committee for establishing standards for what are commonly known as PC Cards. These credit card sized adaptors are widely used in Laptop and Notebook computer for devices such as modem/faxes, networking, secondary storage (harddrives, zip drives), cd roms and other devices. The devices are built into the card or are connected to the computer through a such a card.

2. Card Types

   There are 3 major types of PC Cards, designated as Type I, II, or III. Physically, all three card types have similar length and width (and use the same 68-pin connector. The difference between them is in thickness of the body of the card, Type I conforming to 3.3 millimeters, Type II 5.0 and Type III 10.5 . Type I cards are are typically used for RAM and Flash memory. Type II often used for fax/modems and networking cards are the most popular. Type III cards, the thickest include use with certain storage devices. There are also some extended cards whose body might extend out from the computer because of the device such as antennas for wireless communications.

3. A Short History of PCMCIA
   1. PCMCIA Standard Release 1.0 (June 1990)

      The first release of the standard defined the 68-pin interface and Type I and II form factors. It also provided electrical and physical specifications for memory cards only. It also defined Card Information Structure (CIS) important for card operability and plug and play functions.

   2. PCMCIA Standard Releases 2.0-2.1 (1991-1994)

      A series of updates to the standard the provided specifications for I/O, dual-voltage memory cards, improvements in CIS and software interface (Card Services Specification).

   3. PC Card Standard (February 1995)

      Added information to improve compatibility, support for 3.3 volt operation, DMA support and 32-bit CardBus busmastering.

   4. CardBus, the 32-bit PC Card

      CardBus attempts to do for laptop and notebook computers what PCI (Peripheral Component Interconnect) did for the desktop, namely provide a new design so peripherals can connect to the system with 32 bit memory addressing and data tranfer rather than 16 bit. Also included in this standard is support for bus mastering, which allows cpu functions to be offloaded between the PC Card and that part of the system the card is utilizing. Voltage requirements for CardBus cards are set for 3.3 volts or below. CardBus also supports PC Cards not utilizing CardBus, including backward compatibility with 16 bit cards and 5 volt cards. The original version of Windows 95 released in August 1995 did not support CardBus, however, Windows 95 OSR2 does support it. Additional support is provided by third party vendors such as SystemSoft (http://www.systemsoft.com) and Phoenix Technologies (http://www.phoenix.com) who make card services software to interface such cards with laptop hardware and the computer operating system.

   5. Zoom Video Card and Port

      This is a card that fits into a PCMCIA socket. However, the PCMCIA socket needs to be Zoom Video compliant in order to utilize the card. The Laptops socket can still be used for other PCMCIA cards or adaptors as well. The Zoom Video port standard allows a system to transfer video and audio data through a Zoom card directly to the vga controller, bypassing the sytem bus and cpu. This significantly improves the speed of processing video and audio data. Full screen, full motion movies can consequently be viewed on laptops at about 30 frames per second. Zoom video has hit the market sooner than CardBus and up to now has been implemented on a 16 bit level.

   6. CardBus and Zoom Video

      CardBus is a broader standard that would relate to the development and manufacturing of any PC Card. It establishes 32 bit standards following the same signalling standards as PCI for desktop machines.

      Zoom Video is a more specific solution for faster delivery of video and audio. However, this is only unidirectional in that it flows from the video source to the display.

      Both standards are compatible, though Zoom Video would appear to be a shorter term solution that may not be needed after CardBus is fully implemented.

Note: Not all Toshiba Notebook computers offer Zoom Video Support. In fact, most recent models do not include Zoom Video support.