z486: A 486-Class Pipelined FPGA CPU with Integrated Floating-Point

This is the closer we have for having a full 32-bit x86 system with FPU. Even with the lower precision in the x87 FPU by using the FPGA DSP blocks, eventually having a "486DX" (i486 instruction set + FPU) would enable running a massive amount of PC software (1980..2000's). Taking his z386 core (based in the i386 microcode) and adding 486-class optimizations, including a simplified dual I/D L1 cache, vs the unified but more complex L1 cache in i486's, really is a beautiful and imaginative approach.

> Related work and future work

> ao486 is the closest related open-source design and the CPU behind the established ao486 MiSTer core.

ao486 from 2014 recently mentioned on HN: https://news.ycombinator.com/item?id=49141236