Micro Channel Architecture

What Does Micro Channel Architecture Mean?

Micro Channel Architecture (MCA) is a proprietary 32 and 16-bit bus developed for IBM’s PS/2 computers. Introduced in 1987, the MCA was designed to replace the smaller AT and industry standard architecture (ISA).


In 1988, Intel developed its version of the MCA chip, known as the i82310.

Techopedia Explains Micro Channel Architecture

Prior to releasing the MCA, IBM suffered a setback in the PC hardware market. Challenged by trade issues, where ISA buses could be created by any organization, IBM recreated its bus architecture with proper licensing and regained its market share value.

The MCA bus included an arbitration bus, address bus, data bus, support signals and a set of interrupt signals. Data transfer between input/output (I/O) devices, memory and a controlling master was based on asynchronous and synchronous transmission.

The MCA bus was designed to upgrade ISA features, including:

  • Slow speed
  • Complex configuration
  • Hardwired systems
  • Excessive power distribution
  • Undocumented standards
  • Limited hardware options, I/O device addresses and grounding power

The MCA bus was eventually replaced by the Peripheral Component Interconnect (PCI) bus in the mid-1990s.


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Margaret Rouse is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical, business audience. Over the past twenty years her explanations have appeared on TechTarget websites and she's been cited as an authority in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine and Discovery Magazine.Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages. If you have a suggestion for a new definition or how to improve a technical explanation, please email Margaret or contact her…