Roger’s $0.02 - MiSTer Gaming

The world of retro gaming has been a thing since the advent of the first home Pong machine and Atari 2600 made way for PlayStations and Xbox. Gamers who spent their formative years playing games on older game consoles and arcade machines often have fond, if not entirely accurate, memories of their experiences. Those gamers are two choices. One option is to wait for a compilation game disc filled with the best titles from Midway or Atari. The next option is to turn to emulators.

An emulator is software written to mimic the behavior of old game consoles or computers. As computers grew in sophistication and power it became easier to replicate older game hardware through software emulation. Eventually, a community developed to not only replicate these older machines but also catalog and preserve many of the original games. This classic gaming or retro gaming pastime has in time spawned a cottage industry of magazines, YouTube channels, and emulator coders to support and grow the hobby. The latest development is the use of FPGA or Field Programmable Gate Arrays to emulate old gaming machines on a circuit level for a more “authentic” experience.  Companies selling retro game consoles often rely on this technology for their products.

FPGA or Field-Programmable Gate Array is a type of integrated circuit that can be programmed by a user after its manufacture to create custom and unique processors or ASICs. Users manipulate the portions of the FPGA’s circuit interconnects, like transistors, that form logic blocks of the chip. Manipulating these interconnects allows custom circuit designs to be created, effectively letting the user create a microchip. In a sense, it’s like a blank processor that you can custom-design to tackle specific tasks.

For purposes of game emulation FPGAs offer the closest thing to making vintage gaming boards from scratch. You don’t really need to worry about low-level circuit design. You can emulate all the circuit behavior that made up say the original Nintendo Entertainment System via the programmable logic gates on the FPGA. Now there is the question of why emulation via FPGA is better than software emulation on your desktop computer. Because the FPGA operates on a hardware level you don’t run into the processing overhead you have in software emulation. You can reduce and in some cases eliminate controller input latency and frame rate issues because there are few if any software layers to go through. You can also replicate the errata, the weird mistakes in the original hardware, so games behave in the same way on the FPGA as they did on the original hardware that you really can’t do in software.

The current hotness in this area is the open-source FPGAs project known as MiSTer. The MiSTer is based on the MiST project which aimed to replicate an entire Amiga or Atari ST computer on an FPGA. Issues getting the MiST boards to output to a digital via HDMI instead of an analog display evolved the project into the open-sourced MiSTer. MiSTer efforts are based around the DE10-Nano Kit from TerasIC. The system also supports add-on boards that are stacked on top to offer expanded I/O support for digital and analog signal output, more memory, and more USB ports. The project has also moved beyond just the Amiga and Atari ST and encompasses dozens of 8-bit and 16-bit game systems including the SNES, PC Engine, Genesis, NeoGeo, N64, and others.

Where do you begin if you’re interested in trying out MiSTer? You can check out the MiSTer forum. It contains most of the information you’ll need to start off with to get going with putting together your own MiSTer FPGA. I do recommend, however, you read through the MiSTer wiki to get a good grounding of what the project does and doesn’t do. Also, be aware no game or game ROMs or disk images are included or mentioned. You’ll need to tackle that yourself. Do also understand that the process isn’t cost-free. The price of boards and basic add-ons exceeds $200 USD.

Finally, while FPGA does emulate game hardware on a circuit level it’s still emulation. If you’re a purist for retro gaming hardware the MiSTer project might not scratch that itch. For a good number of users, the MiSTer is a good way to continue playing older video games without cluttering up the home with consoles, wires, and controllers.