A Motorola 68000 running at 10 MHz now has a working PCI bus, built by [maniek86] on protoboard with bare wire, no custom PCB. The machine carries 1 MB of SRAM, 4 KB of ROM, and a MC68681P for UART and I/O. The critical piece is a Xilinx Spartan II FPGA, model XC2S100, wired as a PCI bridge delivering two 32-bit, 5-volt, interrupt-capable slots. A XC95144XL CPLD handles glue logic. No bus mastering, but it runs real PCI cards.
The interesting part is not the finished result but the path to it. [maniek86] documents exactly where PCI implementation breaks down for a non-native architecture and how each problem was resolved. The write-up covers live card integration: a PCI serial expansion board and a Cirrus Logic VGA adapter both operational on a CPU that predates PCI by a decade.
This is the same builder behind an FPGA-based 486-compatible single-board computer covered in January 2026. The full project page at maniek86.xyz and the embedded YouTube demo of the VGA graphics test are both worth your time. Read the original for the bridge implementation details.
[READ ORIGINAL →]