There is just one terminal at MCO. The A & B really just refer to where the airline check-in counters are, as well as where the bags will come out. Each side of the terminal sends you to two "pods" of 30-40 gates. Unfortunately, there is no way to transite between the 1-59 side and the 60-129 side w/o returning to the terminal building and going back through security on the other side.

http://orlandoairports.net/ops/image..._locations.pdf