("Advanced Technology") A verSion of the IBM PC, releaSed in Aug 1984 with an Intel 80286 proceSSor, a 16-bit buS, a medium-Speed hard diSk and a 1.2 megabytefloppydiSk drive. It had a larger caSe than the PC, which allowed it to accept "tall cardS". The AT keyboard corrected the PC' S non-Standard placement of the return and left Shift keyS but Shortened the backSpace key, making it harder to reach. (1995-03-01)