z8086: Rebuilding the 8086 from Original Microcode

After 486Tang, I wanted to go back to where x86 started. The result is z8086: a 8086/8088 core that runs the original Intel microcode. Instead of hand‑coding hundreds of instructions, the core loads the recovered 512x21 ROM and recreates the micro‑architecture the ROM expects. z8086 is compact and FPGA‑friendly: it runs on a single clock domain, avoids vendor-specific primitives, and offers a simple external bus interface. Version 0.1 is about 2000 lines of SystemVerilog, and on a Gowin GW5A device, it uses around 2500 LUTs with a maximum clock speed of 60 MHz. The core passes all ISA test vectors, boots small programs, and can directly control peripherals like an SPI display. While it doesn’t boot DOS yet, it’s getting close.