Baby AT is the motherboard (form factor) format that dominated the personal computer market from the Intel 80286 series of processors until the introduction of the Pentium. It is a variant of the AT form factor, although smaller (hence baby AT). Sets a size for the motherboard of 220 X 330 mm.
It was introduced to the market in 1985 by IBM, and as this variant is smaller and cheaper than AT, soon all manufacturers changed to it and remained as standard on personal computers until it was replaced by the form factor ATX from 1995. The small size, which had been the main reason for its success, was also what motivated its replacement, since as the working capacity of the microprocessors and their heat generation increased, the proximity of the components excessively increased the temperature.
An important feature of this form factor is that motherboards built according to this design were the first to include connectors for different ports (parallel, serial, etc.) integrated in the back and connected internally.
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