CertiGuide to A+ (A+ 4 Real)  9  Chapter 8: Motherboards       9  Form Factors

AT 1 ATX and Mini ATX

As electronics became more miniaturized and more efficient, it became possible to construct a smaller version of the AT known as the Baby AT. The Baby AT measures 8.5 inches (21,59 cm) wide and 10 to 13 inches (25,40 to 33,02 cm) deep. This form factor grew to popularity in about 1997 and although they are commonly found in older motherboards, an updated version of this form factor is still being manufactured. The original Baby AT, like the AT had the processor and memory sticks mounted directly onto the board. This became a problem as both CPUs and RAM sticks became larger. Since modern processor units use large heat sinks and fans, the processor and memory modules often blocked access to several of the expansion slots. This is solved somewhat in newer Baby AT system boards by moving the location of the memory slots. The location of the processor is in the same position on the board. You can also recognize an older Baby AT because it has a single, full-size keyboard connector soldered onto the board. Also, AT and older Baby AT boards do not have a PS/2 mouse connector. The original mice (yes, the actual plural term for a “computer” mouse is “mice”) were attached to the computer by a serial connector.

AT 1 ATX and Mini ATX