When I first heard about roms, it was before I had a computer (around 1994).
it was with a neighboor's Snes Copier, needing floppy disk to play it on the hardware.
then, I got a computer, and I tried the floppy and found that games were files sfc, smc, fig etc.
but, it was not emulated at all.
then, with school friend, we started exchanging first emulators, found on magazine CD.
there were no sound, no transparency, and very slow
but it was the very first step, and since then I followed all the emu scene
now, which was the first rom, I don't remember, and can't because there were a lot already on floppy disk when I heard about it.