Shape factors and standards
The basic badges exist in different forms and with diverse connectors for peripheral. To low the price of costs allowing the intercambiabilidad between basic badges, the manufacturers have been defining several standards that group recommendations on his size and the disposition of the elements on them.
Any way the fact that a badge belongs to one or another category has anything in common, at least theoretically, neither with his services nor quality. The most common types are:
ATX
The badge of the top photo belongs to this standard. More and more common, they go way of being the only ones on the market.
They are supposed of easier ventilation and less jumble of cables than the Baby-AT, due to the laying of the connectors. For it, the microprocessor is placed usually close to the fan of the power supply and the connectors for discs close to the ends of the badge.
The difference "roughly discovered" meets the AT in his connectors, which are usually more (for example, with USB or with FireWire), they are grouped and the keyboard and mouse have in pins mini dough as this one:
. Also, they receive the electricity by means of a connector formed by only one piece (to see top photo). Baby-AT
It was the absolute standard for years. Mm defines a badge of some 220x330, with a few positions determined for the connector of the keyboard, the slots of expansion and the holes of anchoring to the box, as well as an electrical connector split into two pieces.
These badges are the typical ones of the "clonal" computers from 286 up to the first Pentium. With the heyday of the peripheral ones (card sound, CD - ROM, discs extraíbles...) his principal lacks went out to the light: bad circulation of the air in the boxes (one of the motives of the spendthrifts' appearance and fans of chip) and, especially, an enormous jumble of cables that prevents from gaining access to the badge without dismantling at least anyone.
To identify a badge Baby-AT, the best thing is to observe the connector of the keyboard, which almost sure that a pin is a DOUGH wide, like the ancient ones of HI-FI; we go, something like that:
; or to look at the connector that gives the electricity to the badge, which will have to be divided in two pieces, each one with 6 cables, with 4 black cables (2 of each one) in the center. LPX
These badges are of size similar to the Baby-AT, although with the peculiarity of that the slots for the cards of expansion do not find on the motherboard, but in a special connector in which they are punctured, the riser card.
Thus once mounted, the cards remain parallel to the motherboard, instead of perpendicular as in the Baby-AT; it is a typical design of computers of dessert with narrow box (less 15 cm high), and his only problem comes from that the riser card usually does not have any more than two or three slots, against five in a typical Baby-AT.
Proprietary designs
Despite the existence of these standards, the big computers manufacturers (IBM, Compaq, Hewlett-Packard...) usually extract to the market badges of sizes and peculiar forms, well because these designs do not adapt themselves to his needs or for dark and unknown motives.
If you are considering to update a computer "of mark", bear in mind that perhaps another 5.000 has to wear out ptas in a new box, sometimes for motives as irritating as that the augers or the connector of keyboard are to half a centimeter of the normal positions.
Any way even the big ones of the computer science use less and less these badges "to measurement", especially from the arrival of the badges ATX.