It sounds like SpookyAmiga is going to try getting around the different connectors by making something out of 86 position card edge connectors (like the ones that can be removed from dead A2000 boards.) I'll admit I've compared the A2000 CPU slot and A500 expansion port pinouts in the past, they are almost exactly the same. Never got around to trying an A2000 accelerator on an A500 though, worried I might blow it all up.