Behind the designation Advanced Technology (AT) is a bus system for a PC bus and a form factor for the motherboard
. The AT bus is a bus system for personal computers (PC) with advanced technology (Advanced Technology), which followed the XT bus. These personal computers were based on the Intel 80286, 80386 and 80486
at 8 MHz. TheAT slots are a 16-bit bus slot with 62 contacts. In
terms of form factor, the AT motherboard is an obsolete board with one keyboard connector. All other interfaces must be upgraded via expansion cards. Newer motherboards with the AT form factor already have more interfaces.