I / O shield

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Manufacturer-specific I / O shield
Standard cover with openings for (top row from left to right) PS / 2 mouse, Ethernet (RJ-45), parallel port, optional game port and (bottom row from left to right) PS / 2 keyboard, USB ports, RS-232 port, VGA and three optional audio jacks
Various covers. On the left an AT board-compatible cover, bottom two rows and top row: housing-specific covers, deviating from the standard

I / O shield (also ATX cover , I / O cover or connection cover , less often I / O shield , I / O plate or I / O cover ) describes a PC component that leaves the space around the rear closes the external connections of a mainboard and thus ensures electromagnetic shielding . At the same time, by closing the gap, it prevents the inadvertent penetration of objects that may endanger the operational safety of the device (e.g. small metal parts, screwdrivers, plugs or fingers). A positive, but not significant, side effect is the reduction in dust entering at this point in the housing.

I / O Shields are among the formats ATX , micro-ATX, flex-ATX and mini-ITX used the same dimensions. It is a resilient piece of sheet metal that connects the external mainboard connections such as PS / 2 interface , USB , serial or parallel ports , video interfaces such as VGA connection , HDMI , DVI or DisplayPort , LAN and the like. a. perfectly fits into the 159.2 × 44.9 mm recess in the computer case . Since the arrangement of the connections depends on the equipment and design of the mainboard, the sheet metal is usually supplied with the mainboard. In the past, PC cases sometimes included bezels that corresponded to the original designs by Intel. Nowadays this is no longer common. Some cases were built to accommodate AT and ATX motherboards. An I / O shield was used for this, which only left out the five-pin DIN socket for AT / XT keyboards.

function

An I / O shield serves primarily to shield the housing from electromagnetic radiation and secondarily to protect against the ingress of undesired particles. Therefore, the metal sheets are equipped with punched-out contact clips facing the sockets. I / O shields are shaped so that they snap into place in the window of the case.

Since connected to the PC peripherals to be electrostatically charged or potential differences between the device to be connected and the PC can exist must characterized existing charge when connecting via the casing derived are. The external mainboard connections are connected to the housing through the I / O shield.

Connector standards

For motherboard NLX form factor

Connectors Norms
Parallel 25 pin D-sub AMP 787812-1 or equivalent
Serial 9 pin D-sub AMP 787650-4 or equivalent
Video 15 pin HD D-sub FOXCONN DZ11A36-B9 or equivalent
Mouse / keyboard, stack cir DIN FOXCONN MH11067-D2 or equivalent
Audio 5 pin SHOGYO INTNL. SJS-0349A-5P-U or equivalent
RJ45 connector AMP 569564-1 or equivalent
USB single height FOXCONN UB1112C-K1 or equivalent
USB dual stack FOXCONN UB1112C-D1 or equivalent
DB15 MIDI / game port AMP 787201-4 or equivalent
RCA connector HOSIDEN AMERICA JPJ1225-01-040 or equivalent
1394 fire wire MOLEX SD-53460-0611 or equivalent
Optical SP / DIF SHARP ELECTRONICS GP1F31T or equivalent

Web links

Individual evidence

  1. ↑ NLX I / O Shield Design Suggestions ( Memento of the original from March 12, 2017 in the Internet Archive ) Info: The @1@ 2Template: Webachiv / IABot / www.formfactors.org archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 132kb), Version 1.0, May 1997, Intel Corporation.