Joe Burks' OtterX Is an Eight-Bit "Neo-Retro" Machine with Commander X16 Compatibility

Vintage computing enthusiast Joe Burks has designed an eight-bit almost-single-board computer built around a MOS Technology 6502-compatible processor — offering compatibility with the popular Commander X16 project at a lower cost: the OtterX.

"For those asking for a less expensive Commander X16 kit that they could assemble themselves: a DIY, all-through hole, Commander X16-compatible, ITX form factor, eight-bit retro computer kit with an adorable Otter mascot for the industrious retro enthusiast," Burks writes of his creation, referring to it as a "neo-retro mostly through-hole computer" offering "bonus features" above and beyond the Commander X16.

The heart of the system is a Western Design Center 65C02, a current-production equivalent to the classic MOS Technology 6502 found in machines from the Atari 2600 to the Apple II, running at 8MHz — though Burks says the design can also be used to play host to a WDC W65C816, an upgraded 16-bit successor. To this, Burks has connected 40kB of "low" memory, 512kB of "high" memory, and 512kB of read-only memory (ROM) with a 1.5MB RAM expansion in the works — and for those who like more "neo" in their "neo-retro" the CPU can be overclocked to 10MHz.

Elsewhere on the board, which uses primarily through-hole components to simplify assembly for those inexperienced in surface-mount technology (SMT), there are two controller ports compatible with Super Nintendo Entertainment System (SNES) pads, PS/2 connectors for a keyboard and mouse, a Commodore IEC-compatible serial port with floppy disk support, a real-time clock (RTC) with backup battery, and an I2C Grove connector for add-on hardware. The main board uses a VERA board for its video output and an OPM2151 "chiplet" equivalent to the Yamaha YM2151 sound chip.

Burks is making the OtterX available as a kit, with all surface-mount components already installed, via his Tindie store at $274.99; the ITX-format board can be installed in a standard PC case and powered from a 20- or 24-pin ATX-compatible power supply. Additional information, including an assembly guide, is available on the project's Hackaday.io page.