It's also worth adding to Hattig's elegant description, that one of the unique advantages of reproducing the Amiga technology in this particular way is that the hardware designs aren't set in stone (or rather silicon, in this case!). This means the design can tweaked, refined, upgraded and improved as developers create ever-better ways of doing things. This can include finding ways of sidestepping old limitations, or even removing them altogether.
For example: The Amiga AGA chip set was coded to support a fixed 2MB of CHIP RAM. This limited the resolutions etc. which could be supported. That limitation has been removed completely in Minimig AGA / FPGAArcade Replay, which can support unto 50MB CHIP RAM.
Also, one question which comes up a lot is what kind of CPU the Replay etc. reproduces. This question can actually result in confusing or imprecise answers, because it's possible to do things in FPGA which were never done in silicon. For example, what would you rather have: A 68060 running at 100MHz but which is less compatible with software than a 68020 -- or an 68020 which runs at speeds which outperform an 68060, yet has the advantage of offering better compatibility?
I think we'd all prefer the 68020 - but if it makes us feel better, we can call it an 68050 or an 68070, or if NatAmi objects we can call it something else, it really doesn't matter. What matters is what kind of performance we can achieve whilst preserving maximum compatibility too.
In the same way that CPUs can be tweaked and improved over the original designs, the Amiga's graphical and sound capabilities can be enhanced, as well. We can incorporate chunky modes into our FPGA implementation alongside enhanced AGA modes. It can be like having the AAA chipset
and a Picasso graphics card as well, all coded into FPGA!
So, not only is the FPGAArcade Replay not emulation, but it also goes beyond simple cloning too. This allows for the Amiga's design, chip set, to be further improved beyond the capabilities of the original.
