Thanks for mentioning z386. Much of its recent progress was made possible by the reverse engineering and disassembly of the original 80386 microcode (https://news.ycombinator.com/item?id=48247004), which z386 uses as its control program. That work has been especially valuable for reproducing obscure protected-mode behavior correctly.
With correctness helped greatly by that, development is now focused mainly on performance. In Doom, z386 is currently about 30% faster than ao486 on the same MiSTer setup, with benchmark performance roughly comparable to a 486DX2-66.
Can you describe why z386 is much faster than the supposedly highly optimized ao486? Is the original microcode (and corresponding chip architecture) that good?
Comments
Thanks for mentioning z386. Much of its recent progress was made possible by the reverse engineering and disassembly of the original 80386 microcode (https://news.ycombinator.com/item?id=48247004), which z386 uses as its control program. That work has been especially valuable for reproducing obscure protected-mode behavior correctly.
With correctness helped greatly by that, development is now focused mainly on performance. In Doom, z386 is currently about 30% faster than ao486 on the same MiSTer setup, with benchmark performance roughly comparable to a 486DX2-66.
Can you describe why z386 is much faster than the supposedly highly optimized ao486? Is the original microcode (and corresponding chip architecture) that good?