[Coco] FPGA VS Software Emulators

[rcrislip]

On Tue, 25 Jul 2017 19:31:58 +0000
James Ross <jrosslist at outlook.com> wrote:

> FPGA’s are widely accepted to be a more accurate because the
> emulation it’s done at the hardware electrical signal / logic gate /
> precise clock level timings.  For all practical matter it *is* a
> hardware logic circuit.
> 
> The speed issue w/ FPGA is probably two-fold. 
> 
> 1) The FPGA must have an overhead of electrical logic that controls
> the pathways and configures the programmable gates and other logic
> blocks.  That overhead probably affects the final speed of the
> device. Otherwise we would see 2 - 4 GHz devices – like we do CPU’s
> 
> 2) The faster the FPGA the more expensive. So the 50MHz range is what
> is affordable for hobbyist and low budget digital electronic
> development. However, you can get faster for more $$$.  I did a quick
> search, and the claim is made that the Intel Stratix IV is the
> fastest on the market w/ a Core Clock at 600MHz.
> 
> With that said – I read a discussion about a software emulator used
> in a hardware context.  Someone has a proof of concept / prototype of
> a 68020 (or higher) emulator running on an (cheap) ARM CPU off a
> small board w/ the IO’s mapping to the 68020 pins and attaches to a
> real 68020 socket (I think it was an Amiga). If I can find that
> thread, on FB, I’ll post it as a follow-up.
<snip> 

I think you are eferring to the "Ultimate Amiga Emulator (UAE)". To wok
on the Intel PCs, it has to emulate the 68xxx processors and ll the co
processors that made the Amiga what it was. It does it quite well if a
say so myself, especially after the Intel clocks speeds went above
400mz.