A personal computer series from IBM, introduced in 1987 and superseding the original PC line. It introduced four advances: PS/2 connector, 3.5" floppy disk, VGA graphics and Micro Channel bus. See PS/2 port, floppy disk, VGA and Micro Channel. The Micro Channel bus had limited success outside of IBM, but the 3.5" floppy was extremely popular up to the late 1990s. The mouse and keyboard connectors later switched to USB, and the VGA's 640x480 resolution has since become the lowest setting for PC display systems. The PS/2 was the last IBM PC desktop series with radical changes, but IBM did introduce several innovations on its ThinkPad laptops, which were highly praised (see ThinkPad).