Here a question for collectors

Just got 2 machines a 1995 and 2002 machine, both have a (warp) tunnel to center, other machines i have say (in), others are just blank on entrance to path that leads to center area

so here the question, when did (warp, warp out) start/end, when did (in, out) start/end, and is there different word(s) they use on machines for tunnel to center?

Not important, just wondering, seeing 2 new to me machine both say warp, and none of my others say it