(Advanced Technology keyboard) An 84-key keyboard introduced with the PC AT in 1984. The AT keyboard made the Enter and left Shift keys larger, which were too small on the earlier PC/XT keyboard, but the Backspace key was made smaller. See PC keyboard and AT keyboard connector.
Backspace Key Blunder
In the early days of the PC, IBM had a penchant for routinely changing the keyboard layout. More blunders were on their way with the next keyboard (see Enhanced keyboard