This article is about the computer form factor. For the city, see Austin, Texas. For the stock market index, see Austrian Traded Index. The Austrian Traded Index (ATX is the most important Stock market index of the Wiener Börse and the largest trading place in the Austrian economy

The ATX (for Advanced Technology Extended) form factor was created by Intel in 1995. Mini-ITX is a 17 x 17 cm (or 693 x 693 Inches) low-power Motherboard Form factor developed by VIA Technologies. Embedded Platform for Industrial Computing (EPIC is a computer Form factor standard put forth by a combined effort from WinSystems VersaLogic Octagon Systems Micro/sys Nano-ITX is a computer Motherboard form factor first proposed by VIA Technologies at CeBIT in March 2003, and implemented in late 2005 COM Express, a Computer-on-module (COM form factor is a highly integrated and compact PC that can be used in a design application much like an integrated circuit ETX, standing for Embedded Technology eXtended, is a highly integrated and compact (3 ETX, standing for Embedded Technology eXtended, is a highly integrated and compact (3 Pico-ITX is a PC Motherboard form factor announced by VIA Technologies in January 2007 and demonstrated later the same year at CeBIT. PC/104 (or PC104) is an Embedded computer standard controlled by the PC/104 Consortium which defines both a Form factor Mobile-ITX is the smallest x86 compliant Motherboard Form factor. This article compares the IBM compatible Personal computer Motherboard form factors – that is the different sizes and specific or de-facto standards of major system Year 1995 ( MCMXCV) was a Common year starting on Sunday. Events of 1995 It was the first big change in computer case and motherboard design in many years. A computer case (also known as the computer chassis, cabinet, tower, box, enclosure, housing or simply case A motherboard is the central or primary Printed circuit board (PCB making up a complex electronic system such as a modern Computer or Laptop ATX overtook AT completely as the default form factor for new systems. In the area of IBM compatible Personal computers the AT form factor referred to the dimensions and layout ( form factor) of the Motherboard for ATX addressed many of the AT form factor's annoyances that had frustrated system builders. Other standards for smaller boards (including microATX, FlexATX and mini-ITX) usually keep the basic rear layout but reduce the size of the board and the number of expansion slot positions. microATX, also known as µATX (sometimes Transliterated as mATX or uATX on Online forums is a Small form factor standard FlexATX is a PC motherboard Form factor derived from ATX. The specification was released in 1999 by Intel as an addendum to the MicroATX Mini-ITX is a 17 x 17 cm (or 693 x 693 Inches) low-power Motherboard Form factor developed by VIA Technologies. In 2003, Intel announced the BTX standard, intended as a replacement for ATX. Enhancements Low-profile - With the push for ever-smaller systems a redesigned backplane that shaves inches off height requirements is a benefit to As of 2007 the ATX form factor remains the industry standard for do-it-yourselfers; BTX has however made inroads into pre-made systems, being adopted by computer makers like Dell, Gateway, and HP. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Enhancements Low-profile - With the push for ever-smaller systems a redesigned backplane that shaves inches off height requirements is a benefit to The multinational technology company Dell Inc develops manufactures sells and supports Personal computers and other computer-related products Gateway Incorporated is a Computer hardware company based in Irvine, California, which develops manufactures supports and markets a wide range of

The official specifications were released by Intel in 1995, and have been revised numerous times since, the most recent being version 2. 2,^[1] released in 2004.

A full size ATX board is 305mm wide by 244mm deep (12" x 9. 6" ). This allows many ATX form factor chassis to accept microATX boards as well. microATX, also known as µATX (sometimes Transliterated as mATX or uATX on Online forums is a Small form factor standard

Power supply

ATX form motherboards became increasingly popular because of their advantages over older AT motherboards. In the area of IBM compatible Personal computers the AT form factor referred to the dimensions and layout ( form factor) of the Motherboard for

AT-style computer cases had a power button that was directly connected to the system computer power supply (PSU). This article is about the common off-line switching power supplies used in desktop IBM PC compatible computers The general configuration was a double-pole latching mains voltage switch with the four pins connected to wires from a four-core cable. The wires were either soldered to the power button (making it difficult to replace the power supply if it failed) or blade receptacles were used. A solder is a fusible metal Alloy with a melting point or melting range of 90 to 450 ° C (200 to 840 ° F) used in a process called A blade connector is a type of single wire connection using a flat blade which is inserted into a blade receptacle

Typical ATX power supply

Interior view of an ATX power supply.

An ATX power supply does not directly connect to the system power button, allowing the computer to be turned off via software. However, many ATX power supplies have a manual switch on the back to ensure the computer is truly off and no power is being sent to the components. With this switch on, energy still flows to the components even when the computer appears to be "off. " This is known as soft-off or standby and can be used for remote wake up through Wake-on-Ring or Wake-on-LAN, but is generally used to power on the computer through a front switch. Wake-on-Ring (WOR sometimes referred to as Wake-on-Modem (WOM is a specification that allows supported computers and devices to "wake up" or turn on from a sleeping Wake on LAN (WOL sometimes WoL is an Ethernet Computer networking standard that allows a computer to be turned on or woken up remotely by a network message

The power supply's connection to the motherboard was changed. Older AT power supplies had two similar connectors that could be accidentally switched, usually causing short-circuits and irreversible damage to the motherboard. ATX used one large, keyed connector instead, making a reversed connection very difficult. The new connector also provided a 3. 3 volt source, removing the need for motherboards to derive this voltage from one of the other power rails. Some motherboards, particularly late model AT form factor offerings, supported both AT and ATX PSUs.

ATX was originally designed with the power supply drawing air into the case and exhausting it down onto the motherboard. The plan was to deliver cool air directly to the CPU's and power regulation circuitry's location, which was usually at the top of the motherboard in ATX designs. This was not particularly useful for a variety of reasons. Early ATX systems simply didn't have processors or components with thermal output that required special cooling considerations. Later ATX systems with significantly greater heat output would not be aided in cooling by a power supply delivering its often significantly heated exhaust into the case. As a result, the ATX specification was changed to make PSU airflow optional. [1]

With the introduction of the Pentium 4, the standard 20-pin ATX power connector was deemed inadequate to supply increasing electrical load requirements. The standard was revised with an extra 4-pin, 12-volt connector. This was later adopted by Athlon XP and Athlon 64 systems. Various high-end systems may have other forms of supplemental power connections.

Because video card power demands have dramatically increased over the 2000s, some high-end graphics cards have power demands that exceed AGP or PCIe slot capabilities. Not to be confused with PCI-X, a different bus architecture Peripheral Component Interconnect Express, officially abbreviated as PCI-E For these cards, supplementary power was delivered through a standard power connector like those used for hard drives or floppy drives. PCI Express-based video cards manufactured after 2004 typically use a standard 6 or 8-pin PCIe power connector directly from the PSU.

Because the ATX PSU uses the motherboard's power switch, turning on the power in situations that do not utilize an ATX motherboard is possible by shorting the green wire from the ATX connector to any black wire on the connector (or ground). This allows re-use of an old PC power supply for tasks other than powering a PC, but one must be careful to observe the minimum load requirements of the PSU.

The ATX form factor has had five main power supply designs throughout its lifetime:

• ATX — 20 pin connector (Used through Pentium III and early Athlon XP)
• WTX — 24 pin connector (Pentium II and III, Xeon and Athlon MP)
• AMD GES — 24 pin main connector, 8 pin secondary connector (some dual-processor Athlon)
• EPS12V — 24 pin main connector, 8 pin secondary connector, optional 4 pin tertiary connector (Xeon and Opteron) defined in SSI specification
• ATX12V — 20 pin main connector, 4 pin secondary connector, 8 pin tertiary connector (Pentium 4 and mid/late Athlon XP & Athlon 64)
  • ATX12V 1. Pentium III variants Katmai The first Pentium III variant was the Katmai (Intel product code 80525 Athlon is the brand name applied to a series of different X86 processors designed and manufactured by AMD. The Xeon brand refers to many families of Intel 's x86 Multiprocessing CPUs – for dual-processor (DP and multi-processor (MP configuration Athlon is the brand name applied to a series of different X86 processors designed and manufactured by AMD. The Opteron is AMD 's X86 server processor line and was the first processor to implement the AMD64 Instruction set architecture (known The Pentium 4 brand refers to Intel 's line of single- core mainstream desktop and Laptop Central processing units (CPUs introduced Athlon is the brand name applied to a series of different X86 processors designed and manufactured by AMD. The Athlon 64 is an eighth-generation AMD64 architecture Microprocessor produced by AMD, released on 3 — guidance for the −5 volt feed was removed. This was only used by legacy ISA add-in cards. Industry Standard Architecture (in practice almost always shortened to ISA) was a Computer bus standard for IBM compatible computers
  • ATX12V 2. 0 — 20 pin main connector, 4 pin secondary connector (Pentium 4, Core 2 Duo, and Athlon 64 with PCI Express)
  • ATX12V 2. The Core 2 brand refers to a range of Intel 's consumer 64-bit dual-core and 2x2 MCM quad-core CPUs with the X86-64 instruction set Not to be confused with PCI-X, a different bus architecture Peripheral Component Interconnect Express, officially abbreviated as PCI-E 1 — One 20-pin connector, one ATX12V 4 pin connector. Many power supply manufacturers include a 4 plus 4 pin, or 8 to 4 pin secondary connector instead, which can also be used as the secondary EPS12V connector.
  • ATX12V 2. 2 — One 24-pin connector, one ATX12V 4 pin connector. Main Power Connector changed from 20 pin to 24 pin to support PCI-Express requirements.

Dell power supplies

Older Dell computers, particularly those from the Pentium II and III times, are notable for using proprietary power wiring on their power supplies and motherboards. The Pentium II brand refers to Intel 's sixth-generation Microarchitecture (" Intel P6 " and x86 -compatible Microprocessors Pentium III variants Katmai The first Pentium III variant was the Katmai (Intel product code 80525 While the motherboard connectors appear to be standard ATX, and will actually fit a standard power supply, they are not compatible. Not only have wires been switched from one location to another, but the number of wires for a given voltage has been changed. Thus, the pins cannot simply be rearranged. [2]

The change affects not only 20-pin ATX connectors, but also auxiliary 6-pin connectors. Modern Dell systems may use standard ATX connectors. [3] Dell PC owners should be careful when attempting to mix non-Dell motherboards and power supplies, as it can cause damage to the power supply or other components. If the power supply color coding on the wiring does not match ATX standards, then it is probably proprietary. Wiring diagrams for Dell systems are usually available on Dell's support page.

Connectors

ATX I/O plates

On the back of the system, some major changes were made. The AT standard only had a keyboard connector and expansion slots for add-on card backplates. In Computing, a keyboard is an Input device partially modelled after the typewriter keyboard which uses an arrangement of buttons or keys Any other onboard interfaces (such as serial and parallel ports) had to be connected via flying leads to connectors which were mounted either on spaces provided by the case or brackets placed in unused expansion slot positions. In Computing, a serial port is a Serial communication physical interface through which information transfers in or out one Bit at a time (contrast A parallel port is a type of interface found on Computers ( personal and otherwise for connecting various peripherals ATX allowed each motherboard manufacturer to put these ports in a rectangular area on the back of the system, with an arrangement they could define themselves (though a number of general patterns depending on what ports the motherboard offers have been followed by most manufacturers). Generally the case comes with a snap out panel, also known as an I/O plate, reflecting one of the common arrangements. If necessary, I/O plates can be replaced to suit the arrangement on the motherboard that is being fitted and the I/O plates are usually included when purchasing a motherboard. Panels were also made that allowed fitting an AT motherboard in an ATX case.

ATX also made the PS/2-style mini-DIN keyboard and mouse connectors ubiquitous. The PS/2 connector is used for connecting some keyboards and mice to a PC compatible computer system The mini-DIN connectors are a family of multi-pin Electrical connectors used in a variety of applications AT systems used a 5 pin DIN connector for the keyboard, and were generally used with serial port mice (although PS/2 mouse ports were also found on some systems). A DIN connector is a connector that was originally standardized by the Deutsches Institut für Normung (DIN the German national standards organization Many modern motherboards are phasing out the PS/2-style keyboard and mouse connectors in favor of the modern standard of USB ports. Other legacy connectors that appeared on ATX motherboards but are being phased out include 25-pin parallel ports and 9-pin serial ports. A parallel port is a type of interface found on Computers ( personal and otherwise for connecting various peripherals In Computing, a serial port is a Serial communication physical interface through which information transfers in or out one Bit at a time (contrast In their place, on-board Ethernet, Firewire, eSATA and audio ports are increasingly common. Ethernet is a family of frame -based Computer networking technologies for Local area networks (LANs The IEEE 1394 interface is a serial bus Interface standard for high-speed communications and Isochronous real-time data transfer frequently

Variants

There exist several ATX-derived form factors that use the same power supply, mountings and basic back panel arrangement but set different standards for the size of the board.

ATX Scale Reference

References

See also

• mini-ITX
• BTX
• SSI CEB

External links

• ATX Motherboard Specification, v2.2
• Power Supply Form Factors
• ATX12V Power Supply Design Guide, v2.2
• EPS12V Power Supply Design Guide, v2.91
• ATX power supply connectors with pinouts
• ATX Power Supply Links
• More ATX power supply connectors with pinouts
• Motherboard power connectors with pinouts
• ATX Riser Card Specification Revision 1. Mini-ITX is a 17 x 17 cm (or 693 x 693 Inches) low-power Motherboard Form factor developed by VIA Technologies. Enhancements Low-profile - With the push for ever-smaller systems a redesigned backplane that shaves inches off height requirements is a benefit to The Compact Electronics Bay Specification (CEB is a standard Form factor for dual processor Motherboards defined by the Server System Infrastructure (SSI forum 0]
• Small, plug in type ATX PSUs with 12V input