Multi-tasking that didn't suck.

Same as we use it now, to be frank. Unix workstations as an interaction model have persisted so long because it works just great.

I was writing a lot of Unix software in that period - database apps, business logic, and so on. For me, using an MSDOS-based system was a compromise, which I enhanced by using Desqview to get multi-tasking - it allowed multiple MSDOS instances on a single machine, in which I ran terminal software, compilers (our apps were being ported to MSDOS...), and database admin tasks - just like today.

What we have today in the form of MacOS or Linux workstations is pretty much what we had back then, too. The power is inescapable.