The Commodore 1551, the floppy drive for the Commodore 16 and Plus/4, is rare enough in 2026 that Maciej Witkowiak built an emulator called rePico. It does not replace the original hardware wholesale. It keeps the real 6510 CPU and original ROM in the circuit, with a Raspberry Pi Pico emulating only the drive hardware underneath them.
The architecture is the interesting part. A CPLD handles glue logic. An OLED lets users select disk images. The Pico generates the clock signal and IRQ timing that the 6510 expects. The 64K ROM has room for both the factory firmware and enhanced community builds. The project started as a daughterboard for a physical 1551 mainboard, which explains why the design respects the original chip boundaries instead of abstracting them away entirely.
The full schematic and code are on GitHub. Read the project page on Hackaday.io for the rationale behind keeping the original 6510 in the loop, the specific timing constraints the Pico has to meet, and how the CPLD fits between them. That design decision alone is worth the read.
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