From the early 80s  I worked alot with audio-tapes and -cassettes to create the material that I used to create the live radio-broadcasts and mixing shows.
At first, all processing was done by hand :
One technique used a lot was to cut audiocassette-tape  appr. 9-10 cm. long.With a tiny piece of scotch-tape the ends were glued together so that it formed a loop, and it was then placed in a cassette end put to play in an cassette-player. With a little luck, it would play an endless ±4 seconds-long loop.
Having several of these cassette-loops of varied lengths was sometimes enough to fill hours of radio without  it getting over-repetitive, and thus boring.
Another technique was making loops  or repeating clippings by editing ,cassette-to-cassette, with the pause-button.
Both of these techniques were avant-lettre sampling, sort of.

Computers were introduced in the process around 1986,first a Commodore64, and later an Amiga.

Here are some clips of what came out of that:
Basic Material
Radio Broadcasts and/or mixes
Beats