OpenTendo: Open-Source NES Motherboard

A project was recently launched called OpenTendo that’s an open-source hardware recreation of the original 1985 Front-Loading NES motherboard.  This allows you to remove the CPU, PPU and lockout chip from your original NES and transfer them to this board that’s made from 100% brand new replacement parts.  As the main chips are still from original consoles, performance has the potential to be identical or better than original!:

I have so many questions about this exciting project:

  • Which motherboard revision was it based off of, as some NES revisions (NES-CPU-07 & -08) are known to be very high quality, while others (NES-CPU-10 & -11) are known to be noisy.
  • Can Tim and Kevtris use this project to integrate their NESRGB / Hi-Def NES and sell complete, drop-in replacement motherboards?
  • Since the board is open-source, can we update the audio circuit to provide original Famicom audio accuracy, a better sound amplifier and possibly even on-board “stereo” separation control?
  • How is the RF board handled?  Can something like Borti’s NES I/O (and The Real Phoenix’s no-cut version of it) be used in place of the RF?

I reached out to the developer and will follow-up if I receive a response.  It’s an open-source project though, so feel free to take a look yourself!

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