Worked on the mamedev/mame repository to enhance the accuracy of i8089 CPU emulation by addressing a critical bug in the memory-to-memory MOV instruction. Focused on low-level programming in C++, the developer corrected the handling of the PP register during the second half of the instruction, ensuring consistent fixups across both halves. This technical approach improved the reliability of memory operations and reduced discrepancies in edge cases, aligning the emulation more closely with the intended two-instruction sequence. The work demonstrated a strong understanding of CPU architecture and emulation, with targeted validation checks to confirm correct decoding and increased emulation fidelity.