Custom GPU Runs Old Games on New Computers

Combability is always a concern when retro gaming — especially if you’re talking about PC games. Even the cheapest modern GPUs are orders of magnitude more powerful than those from the ‘90s, but they sometimes fail to run ‘90s games properly. The traditional solutions are to resort to emulation/virtual machines or build a PC with parts from the era. But for the past four years, Dylan has been working on an alternative that he’s finally ready to show the world: FuryGPU.

FuryGPU is a PCIe graphics card that works on modern Windows PCs, but with hardware features on-par with a nice GPU from the mid-1990s. The goal is strong compatibility with games from that time period, but on today’s computers. However, this was clearly a passion project on Dylan’s part, because there wasn’t an overwhelming need for a graphics card like this. The other solutions available are probably more practical for most people. Regardless, FuryGPU is very cool and quite impressive.

As you would expect, no manufacturer is still churning out the ICs that would have graced the PCB of a graphics card in the ‘90s. And simply recreating a ‘90s design wouldn’t have suited Dylan’s compatibility goal anyway. Instead, he turned to an AMD Zynq UltraScale+ FPGA.

FPGAs are pretty confusing to the uninitiated, but they’re perfect for projects like this. There isn’t any good terminology in the common vernacular that accurately describes what an FPGA does. In a sense, an FPGA “emulates” hardware — any digital hardware. But it isn’t like software emulation. An FPGA configured to create an Intel 8080 processor is, for example, physically sending electricity through its circuits just like the real deal. But an FPGA has reconfigurable logic blocks, so the engineer can redefine its physical functionality. That same AMD Zynq UltraScale+ could act as an 8080 processor one day, then get a new configuration the next day to act as a FuryGPU.

Here, Dylan took advantage of that fact to create the actual physical circuitry and logic of a GPU. This is exactly what IC designers do before committing to manufacturing a new chip. The FPGA let Dylan create real ‘90s-style GPU hardware without advancing to that manufacturing step, which would be nearly impossible for a maker to do without some serious financial backing.

Dylan taught himself SystemVerilog to “program” the FPGA, designed the GPU for the FPGA, developed a custom PCIe card circuit board for it, and even wrote Windows drivers for the FuryGPU. It has a four-lane PCIe connector and digital video output via DisplayPort and HDMI. Dylan reports that this runs Quake at a consistent 60fps and it is safe to assume that it runs Doom very well, too.

FuryGPU itself will only appeal to a small subset of retro gamers, but we think this project does a great job of illustrating how amazing FPGAs can be. They give makers the ability to create real custom hardware ICs that would normally be out of reach.