Global American supplies PC/104 modules utilizing technologies such as PCMCIA, FLASH SSD, Digital I/O, Flat Panel/CRT SVGA support, Ethernet, and Disk-On-Chip SSD functions. We encourage you to discuss your PC/104 application with our knowledgeable sales personnel for a solution which will enable you to bring your product to the market in the most cost effective and timely manner.

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PC/104

PC/104 (or PC104) is an embedded computer standard controlled by the PC/104 Consortium which defines both a form factor and computer bus. PC/104 is intended for specialized embedded computing environments where applications depend on reliable data acquisition despite an often extreme environment. The form factor is often sold by COTS vendors, which benefits many consumers who want a customized rugged system, without months of design and paper work.[1]

The PC/104 form factor was originally devised by Ampro Computers in 1987[2], and later standardized by the PC/104 Consortium in 1992.[3] An IEEE standard corresponding to PC/104 was drafted as IEEE P996.1, but never ratified.[4]


The standard size of boards complying to the form factor is 3.55 × 3.775 inches (90.17 × 95.89 mm), while the height is typically constrained to the boundaries of the connectors. A constrained height region guarantees that modules will not interfere with their neighbors. Vendors often follow these design restrictions to ensure proper stacking of modules, although it is not uncommon to find boards which ignore the form factor requirements.

While a typical system (also referred to as a stack) includes a motherboard, analog-to-digital converter, and digital I/O (data acquisition) module, other peripherals are finding their way into the market including GPS receivers, IEEE 802.11 controllers, and USB controllers.


Form factors

PC/104
The PC/104 computer bus (first released in 1992) utilizes 104 pins. These pins include all the normal lines used in the ISA bus, with additional ground pins added to ensure bus integrity. Signal timing and voltage levels are identical to the ISA bus, with lower current requirements.


PC/104-Plus
The PC/104-Plus form factor adds support for the PCI bus, in addition to the ISA bus of the PC/104 standard. The name is derived from its origin: a PC/104-Plus module is one which has a PC/104 connector (ISA) plus the PCI connector. One design concern of PC/104-Plus is available board real estate, which is mostly consumed by the bus connectors.


PCI-104
The PCI-104 form factor only includes the PCI connector (with the ISA connector omitted), in an effort to increase the available board real estate. The vast majority of boards still use only the ISA-based PC/104, and are thus incompatible with PCI-104.


EBX
EBX (Embedded Board eXpandable) is a single board computer formfactor, 5.75” x 8.00”. The EBX is based on the IEEE-P996 (ISA), PC/104, PC/104-Plus, PCI and PCMCIA. EBX supports the PC/104 boards.


EPIC
"EPIC" -- an acronym for "Embedded Platform for Industrial Computing" -- the new form-factor sits smack in the middle between the size of the popular PC/104 and EBX embedded SBC standards.

EPIC Express
EPIC Express is based on EPIC, but adds the [[[PCI Express]]].[5][6][7]


Stacks
A system composed of PC/104, PC/104-Plus, or PCI-104 modules is often referred to as a "stack". Although many stacks include modules which are all the same form factor, it is not uncommon to find PC/104 modules in a stack with PC/104-Plus modules.

Each stack must contain at least one motherboard or CPU, which acts as a controller for the peripheral components. The motherboard is often referred to as a single board computer (SBC), for it often has interfaces for all standard PC components (i.e. keyboard, mouse, serial ports, etc.). This controller must support the signaling buses used on all add-in modules. It's possible, however, that a peripheral card may perform a stand alone function without requiring a separate motherboard to control it.

There is no strict limit to the number of PC/104 cards which can coexist in one system. However, as more modules are added, the stack height increases, and signaling requirements may not be maintained. A PC/104 stack will usually have a motherboard controller which is also PC/104. Peripheral PC/104 cards can reside on either side of the CPU.

A stack which has any PC/104-Plus modules must be controlled by a PC/104-Plus motherboard controller. Not counting the PC/104-Plus controller, the number of PC/104-Plus peripheral cards in a stack may not exceed four module slices. This is due to the PCI specification, which allows four PCI components in a system. (More PCI devices may be added if a bridge device is used.) The same rule applies to PCI-104 stacks.