mikej wrote:
"No one has the original chip designs anymore, so the FPGA Amigas are workalikes, they do not behave exactly as the original chips. "
True, but they will be much closer than a software emulation. It is possible to get exact behaviour by running the FPGA core against a real custom and looking for any differences. This is what I've been doing with the Atari chips and will do for the Amiga customs. In this way you can prove the chips behave identically to the originals for all the stuff you have tried, demos, games etc.
If somebody wants to throw money at the problem it is very possible to reverse engineer the logic by examination of a real chip - you scan the chip, strip off the metal layer and repeat. These chips are old so the feature size is large, but it's still expensive.
But, you are right, software emulation is good enough for most things.
/Mike
Ok, I guess you are unaware of the projects...
MiniMig just looks like Amiga for software, that's how Dennis made it. He made no effort to recreate the chips, only to get the software to work.
NetAmi, hasn't been finished and the project developers are not looking for cycle accuracy here... so that will be similar to MiniMig.
CloneA, was built to be cycle accurate. Logic Analyzers were used to to ensure that the FPGAs not only perform the same function but timing is perfect too. This is the closest we will ever get to the Original Amiga. But the DACs are not the same old 80s tech, so the gfx and audio output will be different, subtly...
WinUAE is by far the most accurate and configurable Amiga recreation possible. I can adjust all the settings to match any of my real Amigas. I have software that will work on one model of Amiga and not on another... UAE will run all the software...