jdiffend wrote:
Well, there could be several kinds of emulation.
1. Most instructions are run natively and most unsupported instructions or addressing modes are trapped and emulated by an illegal instruction trap, then execution continues normally until the next one. This would be very fast but probably have 10%-20% slowdown from coldfire safe code and it won't run everything. The code to do this already exists.
2. 100% emulation of the program but OS calls are executed natively by the emulator. Faster than full emulation but slower than the first or last method. The code could probably be extracted from an existing Amiga emulator.
3. 100% emulation with JIT generation of equivalent instruction sequences. It would run any 68k code but would require a lot of work. OS calls would be native and the JIT wouldn't need to examine them.
4. Put the cpu into an FPGA, and debug it. At the end of the day it is easier to do a CPU right, then debug all application code ...
