Clyde Shaffer Prepares to Open Crowdfunding for the Dual-Processor 6502-Powered GameTank Console

Maker and vintage coming enthusiast Clyde Shaffer is looking to launch a modern take on classic games consoles: the dual-processor MOS 6502-based GameTank.

"GameTank is a new video game console based on WDC [Western Design Center]'s modern version of the venerable [MOS] 6502 microprocessor," Shaffer explains of his creation. "Similar in spirit to fantasy consoles like the Pico-8 or TIC-80, the GameTank is set apart by its implementation as a physical hardware device first, and an emulator second. Its custom framebuffer-based graphics architecture allows it to produce smoother and more fluid animations than are typical of eight-bit hardware. Additionally, the audio system is highly configurable, using a second 6502 as a dedicated sound coprocessor."

When Shaffer describes the GameTank as a "new video game console," it's one with an already lengthy history — and not just because it has a pair of processors that trace their lineage back to MOS Technology's release in 1975 and which found their way into devices as iconic as the Commodore 64, Nintendo Entertainment System (NES), and early Apple systems. Shaffer first showed the GameTank off five years ago, promising a device that did things a little differently to rival 6502-based consoles of yesteryear.

"The graphics hardware inside the GameTank differs significantly," Shaffer explains. "Instead of fixed-function tiles and sprites, a region of memory termed a 'framebuffer' contains data for individual pixels of the on-screen image. This is paired with a larger store of off-screen memory 'Sprite RAM' and a blitter circuit, which is dedicated to rapid copy of bytes from Sprite RAM to the framebuffer. The GameTank is designed with a generous amount of Sprite RAM to support large sprite sheets, and because the blitter can copy arbitrarily-sized regions of data, these sprite sheets can be densely packed."

As with Shaffer's early prototypes, the finished GameTank includes a 3.5MHz WDC W65C02S as its main CPU, and a second running at 14MHz and with 4kB of dedicated RAM to provide audio output at a default 14kHz sample rate. The video output takes the form of a square-format 128×128 framebuffer, though Shaffer warns that "some rows on [the] top and bottom [are] hidden by most TVs," and the custom controller offers a four-way direction pad, three fire buttons, plus a start button. Games, meanwhile, are loaded from physical cartridges with 2MB of flash storage — and there's a 26-pin expansion port to the rear for new hardware.

"All of the GameTank’s hardware is open source," Shaffer promises, "including schematics, board files, 3D print files, and part lists. The C SDK [Software Development Kit], the emulator, the client program for the cartridge flasher, and many of the games are all also open source. The console board designs are maintained in both surface-mount and through-hole versions for robotic assembly and DIY soldering, respectively."

Those design files are available on the project's GitHub repository under an unspecified open source license; Shaffer is also preparing to launch a crowdfunding campaign for fully-assembled units, with interested parties invited to sign up on Crowd Supply to be notified when the campaign goes live. For those who want to try the system out first, Shaffer has published a GameTank emulator on GitHub under the permissive MIT license.