IBM PC AT definition computer
("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 megabyte floppy disk 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.