Micro Channel architecture: Difference between revisions

Revision as of 17:13, 12 October 2005

Revision as of 17:17, 12 October 2005

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A final problem was that IBM had lost control of the hardware market for PCs. Anyone could create an ISA card and plug it into any ISA bus-equiped computer. By creating a new standard, IBM would regain control via the required licencing. This motivation for creating MCA, as opposed to selecting an existing standard like [[NuBus]], was based purely on the money IBM felt it could make through the licencing model.

== Design feautresfeatures ==

MCA was primarily a 32-bit bus, but the system also supported a 16 -bit mode which was primarilydesigned to lower the cost of connectors and logic in Intel-based machines like the IBM PS/2.

The situation was never that simple, however, as both the 32-bit and 16-bit versions had a number of additional optional connectors which resulted in a huge number of physically incompatible cards. On the upside, because MCA also moved the pins around to minimize interference, a ground or a supply was located within 3 pins of every signal.

== Data transmission features ==