Thanks for the info, RoushiMSX.

When you say I need a cardridge with a chip matching the one the game was fitted with, how big was the difference between the chips. Were there different revisions of SuperFX or DSP chips except the DSP1/DSP2 and SuperFX/SuperFX 2 issues.

I have a Starfox/Starwing card for SuperFX and a Mario Kart for DSP. I knopw there were games with something like a DSP2, an enhanced DSP. And I know that Star Fox 2 was going to use the SuperFX 2. Then there's that Capcom decompression chip on Mega Man X 2 and 3 and Street Fighter Alpha 2.
If I wanted to get a mostly complete collection of SNES chip cardridges, what games should I get. In other words: which SuperFX card do I need to play Dirt Trax?

Did anybody ever find out why the one pin is not connected in most copiers. It seems to be a common nuisance that you have to reconnect it by yourself. I had to do it on both of my copiers and many people who want to play SuperFX games on copiers hit the same problem.