The Connomore64 C64 emulator is a hardware experiment that ditches the usual path of software-based emulation or pricey FPGA boards. Instead, hobbyist developer c1570 has built a working proof-of-concept using a parallel network of inexpensive RP2040 and RP2350 microcontrollers. The goal? Real-time, cycle-exact Commodore 64 emulation with true signal timing and compatibility with original peripherals.
At its heart, the Connomore64 C64 emulator is an effort to replicate the original system nearly chip-for-chip. The design uses a multiplexed 8-bit bus operating around 8 MHz and supports HDMI for video and audio output. It’s accurate down to microsecond-level timing—fastloaders like JiffyDOS and even the C1541 floppy drive work just as they did in 1985. The system handles real hardware, including userport devices and expansion cartridges like Magic Desk (support pending).
Unlike earlier RP2040-based C64 emulators, this one doesn’t gloss over details. It doesn’t skip CPU cycles or simplify video output—it’s as close to the original timing model as a cluster of €1 microcontrollers can get. That means more accurate VIC-II video emulation, working VSP/AGSP effects, optimized sprite rendering, and a reworked CIA implementation using lookup tables. While not every demo runs flawlessly, most do, and performance in games is solid across the board.
A fork of the rp2040js emulator serves as the development backbone, extended with features like VCD tracing, GPIO latency simulation, and PIO stall monitoring. For visuals, it leverages the PicoDVI library; audio is handled via a SIDKick pico firmware port.
The prototype hardware, dubbed Breadbox v0, fits into an original C64 shell and offers real connectors—IEC, joystick, userport, and more—with HDMI and a headphone jack added for modern setups. The eventual plan? A tiny, low-cost version under €20 using a minimal PCB layout.
The Connomore64 C64 emulator isn’t ready for mainstream use just yet—only half of each C64 CPU cycle is emulated, and expansion port support is still incomplete. But the fact that a cluster of budget microcontrollers can run Katakis, Turrican, and even R-Type speaks volumes about the project’s potential. Check back for updates.
