The IBM Personal Computer AT was released in 1984 as the fourth model in the IBM Personal Computer line, following the IBM PC/XT and its IBM Portable PC variant. It was designed around the Intel 80286 microprocessor.
IBM Personal Computer AT
IBM 5170 with Floor Standing Enclosure and compatible non-IBM display
The IBM Personal Computer is the first microcomputer released in the IBM PC model line and the basis for the IBM PC compatible de facto standard. Released on August 12, 1981, it was created by a team of engineers and designers at International Business Machines (IBM), directed by William C. Lowe and Philip Don Estridge in Boca Raton, Florida.
Internal view of the IBM PC (from the back), showing components and layout. This PC has been outfitted with aftermarket floppy and hard disk drives, but the motherboard and most of the expansion cards are stock.
Original IBM PC motherboard with 16 KB RAM soldered and 48 KB socketed, for a total of 64 KB onboard
Later IBM PC motherboard with 64 KB RAM soldered and 192 KB socketed, for a total of 256 KB onboard
IBM PC with MDA monitor