Z386: An Open-Source 80386 Built Around Original Microcode
Hackaday • • technology
Key Points:
- The z386 project by [nand2mario] implements an Intel i386 CPU on an FPGA using the original microcode, aiming for close compatibility with the original hardware.
- This approach builds on the previous z8086 project, which similarly recreated the Intel 8086 CPU by executing its original microcode.
- The i386 implementation handles a much larger instruction set and complex internal states, including features like memory management, paging, and protected mode extensions.
- The z386 runs on various FPGAs, such as the Altera Cyclone V and Gowin GW5A, achieving performance comparable to a ~70 MHz i386, capable of running software like DOOM despite some cycle efficiency limitations.
- The primary goal of z386 is archaeological reconstruction of the original hardware's behavior rather than outperforming other FPGA CPU cores like ao486.