Joe Burks' OtterX Is an Eight-Bit "Neo-Retro" Machine with Commander X16 Compatibility
Designed to slot into an ITX PC case, the OtterX includes some tweaks above and beyond the Commander X16 that inspired it.
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.