Short for Micro Channel Architecture,

MCA was introduced by IBM in 1987, MCA or the Micro Channel bus was a competition for ISA BUS. The MCA bus offered several additional features over the ISA such as a 32-bit bus, automatically configure cards (similar to what Plug and Play is today), and bus mastering for greater efficiency.


One of the major downfalls of the MCA bus was it being a proprietary BUS and because of competing BUS designs the MCA BUS never became widely used and has since been  phased out of the desktop computers.