The phrase "direct port" refers to a situation where something is copied or transferred exactly as it is from one place to another without any changes or modifications. Full definition
As direct ports of the arcade releases, each game retains much of what hardcore fans can expect from the original games as they were in their traditional arcade cabinets. (gamespot.com)
5.0 - liter V8 with direct port fuel injection. (bestride.com)
Most of the other launch titles are direct ports of games actually available on those systems. (arstechnica.com)