GitHub user dbrll released ll-34, a circuit-level emulator replicating the PDP-11/34A minicomputer. This emulator uses reverse-engineered schematics and microcode to recreate the original hardware's signal-level behavior, distinguishing itself from typical gate-level models. It meticulously models components like the UNIBUS backplane, KD11-EA CPU, and RK05 drives, enabling precise troubleshooting at the hardware level.

Technical significance lies in its circuit-level approach, chosen over Verilog for its ability to reproduce subtle hardware bugs while maintaining performance. The emulator includes a logic analyzer tool crucial for tracing signals and debugging complex ROM timing issues, mirroring the challenges faced with the original hardware. It ships with sample programs including V6 UNIX and Tetris, demonstrating practical utility.

Building and running requires only a C11 compiler, supporting Linux, macOS, and NetBSD. A WebAssembly version with a photorealistic GUI is available, making this sophisticated hardware emulation accessible. This project offers invaluable insights for hardware engineers and retrocomputing enthusiasts seeking to understand vintage PDP systems.