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NESRGB (Tim Worthington)

The reference video mod for the NES / Famicom: a small FPGA board that sits on the PPU and synthesises a clean RGB / component output, where the NES natively outputs only composite (or even RF alone).

Field Value
Systems NES (NTSC/PAL), Famicom, AV Famicom, Twin Famicom, clones
Type FPGA board interposed on the PPU (RP2C02/RP2C07)
Added outputs improved RGB (csync), YPbPr component, S-Video, composite
Level 🟠 fine soldering (PPU removal + socket)
Reversible ✅ if the PPU was socketed (put on a socket)

What it's for

The NES has no RGB: its PPU directly generates a composite NTSC/PAL signal, hence blur, dot-crawl and often jailbars (vertical bars) depending on the board. The NESRGB regenerates the image digitally from the PPU data and re-synthesises clean RGB — with selectable palettes as a bonus (the NES's colour rendering was always "to the manufacturer's taste").

Technical principle

  1. The PPU is desoldered and put on a socket.
  2. The NESRGB board slots in between the socket and the PPU: it spies on the PPU bus (pixel data, sync).
  3. An FPGA rebuilds the image and drives video DACs → RGB + component + S-Video + composite, all clean and synchronised.
  4. The csync is available for SCART (see RGB & SCART).

Compatibility & variants

  • NTSC and PAL board versions (the PPU timing differs).
  • NES-001 models (US toploader = NES-101, Famicom, AV Famicom): kits and ribbons adapted per chassis.
  • Palette switch: button/JP to toggle between several palette renderings (including a much-loved "FirebrandX"-like one).

The PPU must be cleanly socketed

This is the critical step: desoldering a 40-pin PPU without lifting a pad needs a hot-air station or good braid/pump desoldering. A quality turned-pin socket avoids bad contacts.

Installation (summary)

  1. Open the console, remove the motherboard.
  2. Desolder the PPU, fit a 40-pin socket.
  3. Plug in the NESRGB, put the PPU back on top.
  4. Wire the AV multi-out (often a Mega Drive / DIN type connector) on the front or in place of the original output.
  5. Power the board (5 V from the motherboard) and test each output.

Many installers also offer a clean AV faceplate (Multi Out).

Before / after

Criterion Original NES (composite) With NESRGB (RGB)
Sharpness blurry, dot-crawl sharp, crisp pixels
Jailbars common depending on board removed (regenerated image)
Colours fixed palette, sometimes washed selectable palettes, saturated
Outputs composite / RF RGB + component + S-Video + composite

Where to buy

Alternatives

  • Hi-Def NES / analogue-style HDMI (internal HDMI kit, pricier, direct digital output) — see also Nintendo NES.
  • Simple composite/AV mod on RF-only NES units: much worse, but trivial.

Sources & attribution

Review & corrections

How this space is used

Spotted a wrong value, an outdated procedure, a chip reference that does not match your board? Say so here, with what you observed (model, board revision, serial number, measurement). Every report is cross-checked against a source before anything changes — an unverifiable correction is published as “reported by …, not cross-checked” rather than silently applied.

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