i probably stumbled on looping in early 00s, when i rediscovered david torn & started getting some of his music on cd.
in the 90s i had an old yamaha digital delay that had 1.2 sec of delay, but it had a sample mode on it too. i never used it much, but the guitarist i bought it from had demo'd it to me, and he could play (played in a lot of blues/rock bands in the 60s/70s)
throughout the 90s i mostly used it to do "quasi-tape echoplex noises" like tommy bolin would do (or steve stevens), but i could also do simple pitch-shift stuff like bill frisell would do w/ his digitech pds8000. of course not as well as bf of course.
in early 00s i sold my steinberger gl3t, and w/ the $$ i bought a digitech rp100, it had 2 sec of delay, and honestly during the time i had that, i would mess w/ that delay, just glitch the living hell out of playing stuff and manipulate. it was so fun. then shortly after getting it, i got a dod d-12, a 12 sec delay rack unit, but it also had ability to sample 6 sec or 12 sec of material. and once i discovered that, i would mess w/ the 2 sec of delay on the rp100 and dump it into the dod d12...i had a lot of fun messing w/ that for a long time. honestly i'm not sure if i've ever explored what 2 pieces of equipment could do as much or as well as those, but it was a different time. i usually played guitar close to 2 hours a night-our oldest child was pretty young, so he slept most of the time....i don't have nearly that much time now w/ kids activities and coaching basketball!
fun memories though....