ATX and Mini ATX
The first significant change in case and motherboard design in many years, the ATX form factor was invented by Intel in 1995. After three years, ATX is now finally overtaking AT as the default form factor choice for new systems (although AT remains popular for compatibility with older PCs, with homebuilders, and with some smaller PC shops). Newer Pentium Pro and Pentium II motherboards are the most common users of the ATX style motherboard (not surprisingly, since the Pentium II is the newest processor and uses the newest chipset families.) Intel makes the motherboards for many major name brands, and Intel only uses ATX.
The ATX design has several significant advantages over the older motherboard styles. It addresses many of the annoyances that system builders have had to put up with. As the Baby AT form factor has aged, it has increasingly grown unable to elegantly handle the new requirements of motherboard and chipset design. Since the ATX form factor specifies changes to not just the motherboard, but the case and power supply as well, all of the improvements are examined here:
- Integrated I/O Port Connectors: Baby AT motherboards use headers which stick up from the board, and a cable that goes from them to the physical serial and parallel port connectors mounted on to the case. The ATX has these connectors soldered directly onto the motherboard. This improvement reduces cost, saves installation time, improves reliability (since the ports can be tested before the motherboard is shipped) and makes the board more standardized.
- Integrated PS/2 Mouse Connector: On most retail baby AT style motherboards, there is either no PS/2 mouse port, or to get one you need to use a cable from the PS/2 header on the motherboard, just like the serial and parallel ports. (Of course most large OEMs have PS/2 ports built in to their machines, since their boards are custom built in large quantities). ATX motherboards have the PS/2 port built into the motherboard.
- Reduced Drive Bay Interference: Since the board is essentially "rotated" 90 degrees from the baby AT style, there is much less "overlap" between where the board is and where the drives are. This means easier access to the board, and fewer cooling problems.
- Reduced Expansion Card Interference: The processor socket/slot and memory sockets are moved from the front of the board to the back right side, near the power supply. This eliminates the clearance problem with baby AT style motherboards and allows full length cards to be used in most (if not all) of the system bus slots.
- Better Power Supply Connector: The ATX motherboard uses a single 20-pin connector instead of the confusing pair of near-identical 6-pin connectors on the baby AT form factor. You don't have the same risk of blowing up your motherboard by connecting the power cables backwards that most PC homebuilders are familiar with.
- "Soft Power" Support: The ATX power supply is turned on and off using signalling from the motherboard, not a physical toggle switch. This allows the PC to be turned on and off under software control, allowing much improved power management. For example, with an ATX system you can configure Windows 95 so that it will actually turn the PC off when you tell it to shut down.
- 3.3V Power Support: The ATX style motherboard has support for 3.3V power from the ATX power supply. This voltage (or lower) is used on almost all newer processors, and this saves cost because the need for voltage regulation to go from 5V to 3.3V is removed.
- Better Air Flow: The ATX power supply is intended to blow air into the case instead of out of it. This means that air is pushed out of all the small cracks in the PC case instead of being drawn in through them, cutting down on dust accumulation. Further, since the processor socket or slot is on the motherboard right next to the power supply, the power supply fan can be used to cool the processor's heat sink. In many cases, this eliminates the need to use (notoriously unreliable) CPU fans, though the ATX specification now allows for the fan to blow either into or out of the case. See here for more on system air flow and cooling.
- Improved Design for Upgradability: In part because it is the newest design, the ATX is the choice "for the future". More than that, its design makes upgrading easier because of more efficient access to the components on the motherboard
The Embedded ATX specification supports one PCI riser card using a 5 volt 32-bit PCI connector.
A PC riser slot allows for an expansion card to be attached to the motherboard, but in this case the card is mounted horizontal, flat with the motherboard [but raised up].
The EmbeddededATX standard was released by Intel in 2002, as; EmbeddedATX Motherboard Interface Specification.
Pinout tables for embATX power connectors are listed below. The Infrared Port header, USB header and Audio header are not listed
The ATX pin out is really a group of dual pin headers located on the Mother board.
The Mini-ITX mainboard form factor is a highly integrated native x86 mainboard measuring only 170mm x 170mm and enables the development of an infinite variety of small form factor PC systems. More than 33% smaller than the FlexATX mainboard form factor, the Mini-ITX is aimed at the development of Thin-Clients, wireless network devices, digital media systems, set-top boxes and more.
A key advantage of the Mini-ITX mainboard is that it is based on the low power VIA processor platform that comprises of either a VIA C3™ processor or a fanless VIA Eden™ ESP processor, together with a choice of highly integrated VIA chipsets and VIA companion chips.
|
VIA EPIA Mini-ITX Mainboard from VIA Embedded Platform DivisionThrough its mainboard business unit VIA Embedded, VIA produce the VIA EPIA Mini-ITX Mainboard for small, quiet PCs ranging from silent desktops to digital media rich Hi-Fi and entertainment PCs. You can download high and low resolution pictures, BIOS, drivers, manuals, and datasheets for VIA EPIA Mini-ITX mainboards from the VIA Embedded website. Trailblazing into an exciting new market, there is an increasing number of independent chassis, power supplies and other accessories manufacturers for the Mini-ITX form factor. For information on where to buy VIA Embedded Mini-ITX mainboard as well as information on what chassies are available, please go to the VIA Arena web site or contact our VIA Embedded channel partners from the VIA Embedded web site. |
VIA EPIA Mini-ITX Case Mods and Car PC ProjectsWith the I/O ports as the tallest components on the board (including the CPU cooler), the Mini-ITX mainboard is also becoming increasingly popular among the rapidly emerging enthusiast user group. The small size, quiet operation and low profile of the VIA EPIA Mini-ITX makes it ideal for moving the PC to different parts of the home, from stylish case modifications for the living room to in-car PCs. With the VIA EPIA Mini-Itx, your imagination is its only limitation! |
The Mini-ITX mainboard successfully integrates various combinations of readily-available chipset and processor components from VIA that come with rich feature sets that include ultra low power native x86 processors, onboard LAN and various integrated AGP graphics and audio options. Further enhancing its versatility, the Mini-ITX mainboard can include CompactFlash and CardBus slots, TV-Out connector, SPDIF 5.1 audio, USB 2.0, 1394 (Firewire), integrated MPEG2/MPEG4 decoding, support for up to DDR400, Serial ATA and much more. 
VIA processor platforms are unique in that the workload is shared across the whole platform rather than being focused on the CPU, i.e. platform centric as apposed to CPU centric. Due to their low power consumption, these platforms generate less heat and therefore require less active cooling, allowing the use of quieter, lower profile coolers that are better suited to the ergonomic, small form factor systems that have more application flexibility than the more traditional tower PC.SSI CEB
The Compact Electronics Bay Specification (CEB) is a standard form factor for dual processor motherboards defined by the Server System Infrastructure (SSI) forum. The specification is intended for value servers and workstations based on the Intel XEON processor.
An SSI CEB motherboard is 305mm x 267mm [12” x 10.5”].
The SSI CEB specification was derived from the EEB and ATX specifications. This means that SSI CEB motherboards have the same mounting holes and the same IO connector area as ATX motherboards, although SSI CEB motherboards are larger in size than ATX motherboards. The rear panel aperture is identical to the EEB and ATX specification and expansion cards mounted on an SSI CEB motherboard appear much the same as they would on an ATX motherboard.
To standardize thermal behavior of such motherboards the position of the processors is defined, including the identification of the primary processor and the secondary. For motherboards with only one processor, it is recommended that the primary processor should be provided first.
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 acquisitionCOTS vendors, which benefits many consumers who want a customized rugged system, without months of design and paper work. despite an often extreme environment. The form factor is often sold by
The PC/104 form factor was originally devised by Ampro Computers in 1987, and later standardised by the PC/104 Consortium in 1992. An IEEE standard corresponding to PC/104 was drafted as IEEE P996.1, but never ratified.
Unlike the popular ATX form factor which utilizes the PCI bus and is currently used for most PCs, the PC/104 form factor has no backplane, and instead allows modules to stack together like building blocks. The stacking of buses is naturally more rugged than typical PCs. This is a result of mounting-holes in the corner of each module which allow the boards to be fastened to each other with standoffs.
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
[edit] 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.
[edit] 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.
[edit] 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.
[edit] 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.
[edit] 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.
The EPIC spec allows I/O connections to be implemented as either pin-headers or PC-style ("real world") connectors. The standard provides specific I/O zones to implement functions such as Ethernet, serial ports, digital and analog I/O, video, wireless, and various application-specific interfaces
Form factors
[edit] 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.
[edit] 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.
[edit] 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.
[edit] 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.
The EPIC spec allows I/O connections to be implemented as either pin-headers or PC-style ("real world") connectors. The standard provides specific I/O zones to implement functions such as Ethernet, serial ports, digital and analog I/O, video, wireless, and various application-specific interfaces
Pico-ITX
Pico-ITX is a PC motherboard form factor announced by VIA Technologies in January 2007 and demonstrated later the same year at CeBIT. The Pico-ITX form factor specifications call the board to be 10 x 7.2 cm (3.9 in x 2.8 in), which is half the area of Nano-ITX. The processor can be a VIA C7 or a VIA Eden V4 that uses VIA's NanoBGA2 technology for speeds up to 1.5 GHz, with 128KB L1 & L2 caches. It uses DDR2 400/533 SO-DIMM memory, with support for up to 1GB. Video is supplied via AGP by VIA's UniChromeGPU with built-in MPEG-2, 4, and WMV9 decoding acceleration. The BIOS is a 4 or 8 Mbit Award BIOS.[1][2] Pro II
EPIA PX (currently the only motherboard series that uses the Pico-ITX form factor) has been demonstrated running Microsoft Windows XP and Windows Vista[3]. Major current flavours of Linux, including Fedora Core 6 and Ubuntu 7.10, have also been shown to be able to run on it.
EPIA PX10000G
The first motherboard in this form factor is called EPIA PX10000G. It is 10 x 7.2 cm and 10 layers deep. The operating temperature range is from 0°C to about 50°C. The operating humidity level (relative and non-condensing) can be from 0% to about 95%. It uses a 1 GHz VIA C7 processor a VIA VX700 chip set, and is RoHS compliant.[4] It has onboard VGA video-out, VIA VT6106S 10/100 RJ45 Ethernet, UDMA 33/66/100/133 44-pin PATA (1x), and SATAI/O. DVI and LVDS video-out, USB 2.0, COM, PS/2 Mouse & Keyboard, and 7.1 channel audio (supplied by a VIA VT1708A chip) are supported through the usage of I/O pin headers and add-on modules.[5][6] (1x)
The VIA PX-O add-on module supplies access to: 1 RCA-out for S/PDIF usage, 4 USB 2.0 ports, 1 Mic-in, 1 Line-out, 1 Line-in, 1 buzzer/speaker, 1 CN9 Connector (function TBC), and 1 CN10 Connector (function TBC). (Note: Either the VIA PX-O add-on module or 4 USB 2.0 I/O are supplied in retail packages.)[7]
The VIA VT1625M add-on module supplies access to 1 External TV-Out and 1 Video Capture Port.[8]
No comments:
Post a Comment