Sorry, I rather meant before VM technology became widely used by consumers in the context of running a second OS instance and applications on their home systems. I still have my copy of the originsl VMWare Workstation ca. late 90s and before that I ran an MSDOS emulator on my Atari ST ca. late 80s - early 90s - though Im not sure about its technical standing vis a vis a true VM. IIRC, I first read the book comparison r.e. multiple copies of software used by Microsoft (?) years before that. Perhaps my timeline is still off though. 

N.B. The first reference I found (in a very cursory search),  to books and software copying  was in the 1981 issue of Compute! magazine (which also touted the release of the Commodore Vic 20(1981). Don't know if it was in any EULAs at the time, but I doubt most home computer users of the era had any idea what a VM was :-)  

"Democracy is a pathetic belief in the collective wisdom of individual ignorance." - H. L. Mencken