Jeff Dionne, Rob Landley, and Shumpei Kawasaki are reviving Hitachi's Super H architecture, an open-hardware alternative to x86 and ARM. The Super H SH2, known for its dense instruction set, inspired ARM's Thumb design. With patents expiring (last SH2 patent in 2014), the team developed J2, a clean-room core implemented in VHDL for Xilinx Spartan6 FPGAs or ASICs. J2 can run Linux on low-cost hardware, requiring minimal components like a 32-bit memory space and GCC. A $50 FPGA demo booted Linux 3.4, sparking applause. Future J2+ (2016) adds SMP and DSPs for IoT, while J4 (SH4-based) targets set-top boxes. ASIC fabrication costs ~3 cents per chip at 180nm. The project leverages existing kernel/GCC support, avoiding reinvention. Kickstarter aims to create a Raspberry Pi-compatible board with a powerful FPGA for J4 compatibility.

J2 inherits Super H's efficiency, excelling in instruction density. This reduces clock cycle dependency, critical for performance. Unlike open cores like RISC-V, J2 reuses mature code, accelerating development. Landley noted, "We didn't write new code; we dusted off existing work." The team collaborates with former Hitachi engineers but focuses on affordable hardware.

The project's open-source ethos aligns with Dionne's advocacy for open software on open hardware. Modern devices host countless ARM/MIPs chips for peripheral tasks, yet x86 dominates CPUs. Super H offers a cost-effective, patent-free alternative. J2's success hinges on expiring patents and community engagement. A 2009 study ranked Super H ahead of most architectures except x86 variants.

The team plans documentation via nommu.org and 0pf.org, plus a Kickstarter for a development board. Challenges include scaling to J4's SIMD arrays. Despite limitations, J2 proves Super H's viability for disposable computing, targeting low-cost IoT and medical devices.