Submitted Al MacInnis, Jan 26 2002 12:59 PM | Last updated Jan 26 2002 12:59 PM
IBM's PS/2 32-bit expansion bus.
In 1987, IBM created the PS/2, with a 32-bit expansion bus, to replace the original PC's ISA 8 bit (and later 16 bit) buses.
The MCA bus was patented, so other brands than IBM couldn't use them. That has lead a consortium to create EISA bus.
Very few cards are in MCA bus nowadays.