6o6 / 6502 / c64

A Hacker News post highlights “6o6 v1.1,” an update to a 6502-on-6502 virtualization project described as improving performance for emulating classic 6502-based systems. The linked blog post (oldvcr.blogspot.com) says the new version is faster, targeting emulation use cases such as Commodore 64, Apple II, and Apple-1 environments. The item appeared on Hacker News about an hour before capture, posted by user “classichasclass,” and had 12 points at the time shown. Beyond the title and brief listing, the provided content includes no technical benchmarks, implementation details, or release notes, so the specific optimizations and measured speed gains cannot be confirmed from the excerpt alone.

The open-source 6o6 v1.1 update improves a 6502-on-6502 virtualization library—an NMOS 6502 software core written in 6502 assembly that runs on vintage machines like the C64 and Apple II. The release trims a hot-path instruction, optimizes addressing modes, adds a faster direct-store path for zero page, and provides finer control over the 6502 interrupt flag. 6o6 uses a harness/kernel model where the harness mediates all guest memory access, enabling flexible virtual memory (paging, synthesized memory, faults) and example projects like running EhBASIC from paged geoRAM. Performance gains come from heavy use of xa65 assembler macros to inline memory-access code and enable primitive instruction fusion, reducing call/return overhead in the VM hot path.

6o6 v1.1: Faster 6502-on-6502 virtualization for a C64/Apple II Apple-1 emulator

A developer released 6o6 v1.1, an optimized 6502-on-6502 virtualization layer that accelerates emulation for vintage systems like the Commodore 64, Apple II and Apple-1. The update improves performance by refining instruction dispatch and cycle accounting, reducing overhead when running a 6502 CPU emulated on real 6502 hardware, and adds bug fixes and timing tweaks for better compatibility with real-world ROMs and peripherals. This matters to retro computing enthusiasts and hardware hackers who build FPGA/TTL and software hybrids or run cross-emulation on vintage boards, because it makes authentic system behavior more accurate while lowering resource needs. The release highlights ongoing niche innovation in low-level emulation and preservation of classic platforms.