RS-232 (Recommended Standard 232, also known as EIA/TIA RS-232C) is an interface that designates a standard for the exchange of a series of binary data between a DTE (Data Terminal Equipment) and DCE (Data Communication Equipment , Data Communication Equipment), although there are others in which the RS-232 interface is also used. An equivalent definition published by the ITU is called V.24. The RS-232 is a connectorDB-25 type (25-pin), although it is normal to find the version of 9-pin (DE-9, or popularly also called DB-9), cheaper and even extended to certain types of peripherals (such as serial mouse PC).

A Peripheral Component Interconnect (PCI, "Peripheral Component Interconnect") is a bus (picture 2) computer standard for connecting peripheral devices directly to your motherboard. Dimensions of the cards - PCI (standard) 107 mm x 312 mm (picture 1) - PCI Low Profile Height: 36.07 mm x 64.41 mm Depth: 119.91 mm to 167.64 mm - Mini PCI Mini PCI cards have a Maximum consumption2W.

The RS232 connector is a connector type 9-pin connector is popularly called Series. It is a connector that was once widely used by various components of the PC, such as a mouse, keyboard ... but over time it has fallen into disuse and replaced by the USB connector trying to emulate the latest version number. It is currently used by robots, elevators, POS and industrial machinery.

ATX corresponds to a standard that was created to improve Baby-At. The idea of ??this improvement was rejoining carasterísticas to improve the speed and what it cost to mount a plate. ATX measures are 30.5 cm x 24.4 cm. From here in the ATX format we can be found different formats - E-ATX has measure 30 cm by 33 cm - ATX-30 having a measurement 30.5 24.4 cm - Mini ATX has a measure x 28.4 cm