Thriller was made in 3 months and released in December of 1982 whereas (as far as I know) the Yamaha DX7 came out in 1983.
The aforementioned title track (composed by Yorkshireman Rod Temperton) features at least an LM-1 drum machine, Rhodes and Roland Jupiter-8. Vocals were compressed with LA Classics Class A silverface 1176LNs and it was mixed on a Harrison 32c desk.
It's known that Quincy Jones (the song and album's main producer) sometimes used a Yamaha CS-80 in recordings of that period.
It's my guess that the Thriller bassline was played on a Minimoog.
[This message has been edited by Misnomer (edited 03-31-2003).]