When I first started in audio, digital recording was largely unheard of except amongst the theorists. Recording was done to analog tape. Editing was by razor blade and adhesive tape.
My first exposure to digital editing was the JVC DAS system, an alternative to the Sony PCM-1630 system that was the backbone of CD mastering for many years. Both systems were built on video technology then in common use in broadcasting. Digital audio was recorded as black and white dots on 3/4-inch U-matic videotape cassettes. "Insert editing," as can be done with linear analog tape by inserting a section of tape into the middle of a recording (to extend a recording, or, to reorder portions of a recording or a collection of recordings), was impossible. Instead, you used what was essentially a customized video editor to "assemble edit" a master, locking two machines together and then dubbing material section by section into a new recording—record from the "master" to the "slave" a bit past the first edit point, replace the master with the source tape for the next chunk of an alternate mix and "scrub" with the shuttle wheel to find the edit points on both tapes, lock in the offsets and autorehearse the edit to make sure you had it right, then execute the edit and record a bit past the next edit point, repeating ad nauseam.
You could physically edit linear digital tape much as with analog tape (the system available at the time was the Mitsubishi/Otari PD 32-track, 1-inch reel-to-reel, and Mitsubishi 2-track 1/4-inch), but editing was very sensitive to error. You could "punch in" material in the middle of a recording, but not extend a recording by insert editing except by cutting and splicing. So, there too, recordings were most commonly assembled edited. On the reel-to-reel digital recorders, this was done with two machines, dub cables, synchronizers, time code and word clocks, locking two machines together and building a song piece by piece (I once spent near 90 hours across a few weeks working with an artist to build an entire album in assemble edit fashion, taking bits from three to five takes per song).
Digital audio workstations were born as editors, with limited storage capacity and rudimentary processing capabilities—in some ways analogous to analog tape editing, but so very much more powerful, with random-access editing capabilities, no rewind times and the ability to slip and slide individual tracks with ease. I was reminded of this history by the Digidesign Pro Tools 8 review in this issue, which vividly illustrates how far DAWs have advanced in just a few short years, now effectively housing near the entirety of a very sophisticated studio signal chain including a bag of tricks that didn't even exist in previous recording paradigms.
Viva La Revolution!