Meaning – The term micro channel architecture, refers to the rules that define how subsystems and adapters use the Micro Channel bus in a computer. The architecture defines the services that each subsystem can or must provide.

It is an expansion bus created by IBM that was used in the company’s PS/2 desktop computers. An expansion bus allows additional cards to be connected to the computer’s motherboard, expanding the number of I/O ports. These include SCSI, USB, Firewire, AGP, and DVI connections, as well as many others.

The MCA standard was designed to take the place of the AT and ISA buses used in previous IBM PC/AT compatible computers. While the MCA bus architecture was an improvement in both size and speed over AT and ISA, it was kept as a proprietary standard by IBM.

Example of usage“The Micro Channel was primarily a 32-bit bus, but the system also supported a 16-bit mode designed to lower the cost of connectors and logic in Intel-based machines like the IBM PS/2.”