An AT bus is a type of computer bus used in IBM-compatible personal computers. It was introduced with the IBM PC/AT in 1984 and is designed to connect various hardware components, such as graphics cards, sound cards, and storage devices, to the motherboard. The AT bus operates at a 16-bit data width, allowing for faster data transfer compared to its predecessor, the ISA bus. The AT bus supports a maximum clock speed of 8 MHz and can accommodate up to 16 devices. Although it has been largely replaced by faster buses like the PCI bus, the AT bus played a significant role in the development of PC architecture and remains a foundational concept in computer hardware design.