Clyde Shaffer’s Game Tank Is an Amazing 8-Bit Video Game Console
The Game Tank is an 8-bit video game console that was built completely from scratch and that already has a great platformer game
Today’s video game consoles are, essentially, just computers wrapped up in proprietary packages. The Xbox One and Xbox Series X, for example, run operating systems built on Windows 10 Core. The PlayStation 4 and PlayStation 5 have operating systems based on FreeBSD. The Nintendo Switch has a modified version of Linux. But early video console games ran much closer to the “metal,” with games often being written in Assembly code. Clyde Shaffer has been on a quest to develop a brand new console that follows that traditional style. The result is an 8-bit video game console called Game Tank that was built completely from scratch, and Shaffer has even successfully programmed a game for it.
Most of the modern 8-bit consoles we see are made using a number of “cheats” that make the process faster, easier, and cheaper. They’re typically built around modern microcontrollers or entire development boards. Even when retro processors are used, those microcontrollers are often implemented to handle video or peripheral connections. Shaffer did not want to utilize any such shortcuts in the Game Tank. His entire console design is based on components that were available during the 8-bit era or that are similar to those that were. It doesn’t have any modern microcontrollers or an FPGA to simplify the hardware. It would have been very expensive to develop something like this in the ‘80s, but all of the components are relatively cheap today. That means that Shaffer was able to make a console that is superior to those of the era in many ways.
Game Tank is built on a 6502 processor, similar to the original Nintendo, running at 3.5MHz with 8KB of RAM. It has a 128x128 framebuffer with a 128x100 on-screen resolution through NTSC composite video output. The framebuffer has a nifty dual-ported RAM setup for the composite video signal generator and a dedicated memory copy controller that can move bytes in and out of the video RAM without having to take up software loops. It has four channel sound output with two square wave generators, LFSR noise, and a wavetable. Due to a part supply issue, Shaffer is considering replacing that with a different soundcard design that utilizes a second 6502 processor as an 8-bit DAC (digital-to-analog converter) for audio synthesis.
Like all of the great consoles in history, Game Tank accepts cartridges — though SPI is available for communication, as well. The controller port is compatible with Sega Genesis controllers, which have connectors that are easy to source today. Shaffer has even programmed a playable game for the Game Tank. It’s a platformer called Cubicle Knight that has surprisingly good graphics and that looks quite fun to play. The best aspect of the Game Tank is that it is purposefully designed to be built by other makers. All of the PCBs are designed for through-hole components and those components are all still being produced today. The design files have been published on GitHub, so you can build your own Game Tank and start helping out with game development!
