Micro Channel Architecture
(MCA) IBM's proprietary 32-bit bus, used in high-end PS/2 personal computers. Micro Channel is designed for multiprocessing. It eliminates potential conflicts that arise when installing new peripheral devices. MCA is *not* compatible with either EISA or XT bus architecture so older cards cannot be used with it.
As with the ROM BIOS in the first IBM PCs, figuring out the Micro Channel's secrets has been an arduous task of reverse engineering ever since the PS/2 line was announced. Consequently, the MCA has never become as wide spread as the competing EISA standard.