MCA

Micro Channel Architecture (MCA) Bus
Ways in which MCA was "ahead of its time", with explanation of its demise.
http://www.pcguide.com/ref/mbsys/buses/types/olderMCA-c.html

Peter H. Wendt
IBM Microchannel Enthusiasts Page including his famous QBMCA Microchannel Adapter Identification Software and hundreds of ADFs for IBM MCA-machines.
http://www.mcamafia.de/mcapage0/mcaindex.htm

Quatech: Microchannel Bus Overview
Describes MCA's improvements over ISA, plug-and-play system, and a few specs.
http://www.quatech.com/support/comm-over-mca.php

Su's PS/2 Page
The effects of M.A.D. Microchannel Addictive Disorder.
http://www.utdallas.edu/~swadlow/ps2linux/

Tavi PS/2 Pages
Information about IBM PS/2 machines. Although mainly directed at the MicroChannel systems (model 50 and above) there may be the occasional snippet about the lower end ISA-based systems as well.
http://www.tavi.co.uk/ps2pages/

TechFest
Micro Channel Bus technical summary.
http://www.techfest.com/hardware/bus/mc.htm

What is MicroChannel Architecture?
IBM's answer to the failings of its older PC bus, which is now referred to as the ISA bus, article discusses the problems and short falls it had.
http://kb.indiana.edu/data/acae.html