Coldfire and 68K are about 99.8% code compatible. That's been the case from the start, Freescale didn't change it. There are two problems to solve with a coldfire card for Amiga.
#1 There are instructions in the 68k that are also legal on the coldfire... but they do a different type operation. It would be better if these instuctions were excluded on the coldfire all together. That way you could trap them with an illegal op exception and direct the code to a lib that would do a compatible operation in software instead. Many missing instructions are handled this way with current methods. The trouble comes in dealing with the "alien" instructions that do exist and can't be trapped. Some have suggested a JIT compiler method to intercept every binary code and process it. But that would require lots more code, probably more hardware and sap the speed of the coldfire down to an estimated 060/50 at best. It's a challenging problem that no one (that we know of) has solved yet.
#2 is the IO architecture. Only certain coldfire models support the necessary input/output options to interface well with the Amiga system. Hardware designs would have to be worked out to deal with the motherboard/buss interfaces.
There might be an Option #3.....
Use this instead....
http://www.innovasic.com/fido.htmas suggested in this thread....
FIDO 1100 MPUIf this CPU executes every included instuction like a 68k, then missing instructions can be handled in software.
Plaz
