Hi john.

There's a reasonable free VSTI emulation of an FM synth called GTG FM4. You can find it on this page.

http://www.gtgsynths.com/plugins.htm

Back in the 80s we used to play "Spot The Preset". As you say, nearly all the 80s tracks seemed to be made up of DX7 sounds. I sold my DX7 recently when it became a two-man lift!

ROG.