The Commodore 64 is an integral part of the time machine.
Year of feature (shown above)
This movie was also featured as a Mystery Science Theater 3000 episode in 1997 (#821): http://www.mst3kinfo.com/daddyo/di_821.html
I have travelled here from 1982 to tell you that the use of Commodore 64s as an integral part of a time machine is in fact very realistic and deserves 5 stars. I am now travelling back to the 1982 to play the copy of Elite which I picked up, on the way here, in 1985. Bye!