The Personal System/2 or PS/2 is IBM's second generation of personal computers. Released in 1987, it officially replaced the IBM PC, XT, AT, and PC Convertible in IBM's lineup. Many of the PS/2's innovations, such as the 16550 UART, 1440 KB 3.5-inch floppy disk format, 72-pin SIMMs, the PS/2 port, and the VGA video standard, went on to become standards in the broader PC market.
The original IBM PS/2 mouse
PS/2 connection ports (later colored purple for keyboard and green for mouse, according to PC 97) were once commonly used for connecting input devices.
MCA IBM XGA-2 Graphics Card
Some PS/2 models used a quick-attachment socket on the back of the floppy drive which is incompatible with a standard 5.25" floppy connector.
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