A replacement for the Full AT motherboard and sometimes referred to as BAT, the Baby AT is a motherboard form factor introduced by IBM in 1985 and used for many 286, 386, 486, and Pentium computers up until the early 1990s. The Baby AT is 8.57" wide x 13.04" deep, which is almost the same as the original IBM XT motherboard with modifications in the screw hole position to fit into AT-style case. This board is now considered obsolete and has been replaced by ATX.
