What is it?

A new way to play your Gameboy Advance games on a high definition TV with stunning visual clarity and very low input lag. The GBA HDMI adapter is an FPGA-based mod kit for the Gameboy Advance adding the ability to have an HDMI video output. The Gameboy Advance video is processed to produce an accurate representation that is at the correct aspect ratio, with none of the stutter that plagues the Nintendo Gameboy Player.

What are the specs and features?

The GBA HDMI Adapter outputs digital video over a mini HDMI connector at a resolution of 1280x720 and uses full 4:4:4 RGB for maximum quality. The audio is taken directly from the GBA SOC PWM audio output and digitally decoded for maximum quality, bypassing the need for noisy analog-to-digital conversion. This audio is embedded directly in the HDMI stream.

By default the GBA HDMI Adapter runs at 60 Hz vertical refresh, requiring the GBA itself to run with a slight overclock of 1.004% from its original speed. An alternative FPGA bit file will be available which will set the HDMI output at nearly 59.7276 Hz vertical refresh rate. In this mode the GBA is running within 0.000001% of the Nintendo specification, closer to spec than the cheap crystal the GBA was shipped with. Both modes are low latency, tear free, and stutter free.

The adapter supports both 4x and 5x nearest neighbor scaling. 4x scale is used for GBA games, the output is set at 960x640 letterboxed image in a 1280x720 frame, with aspect ratio properly maintained. 5x scale is for Gameboy and Gameboy Color games allowing them to fill the screen vertically.

The user has a choice between the default colors produced by the GBA, or four altered color sets. Credit goes to user "Pokefan531" for providing the color correction coefficients from which these color sets were derived from.

Default

Color Tone A2

Default

Color Tone A1

Default

Color Tone A1

For Gameboy games, the user can select from 40 different palettes from the Super Gameboy. Below are a few of the available palettes.

You can choose from a scanline or gridline image overlay is with varying intensity.

Gridlines 12.5% strength

A SNES controller can be plugged into the GBA HDMI adapter to control the Gameboy Advance. If you prefer, you can just use the Gameboy Advance to control the game. The GBA HDMI adapter also supports the 8Bitdo retro receiver, allowing for the use of a Bluetooth SNES controller or the Wii U Pro controller. The external controller is also used to navigate the video settings menu. The user video settings can be saved to the on board memory and will be loaded automatically at startup. Power is provided via a micro-USB cable. This device consumes very little current and can be powered from a 500mA TV USB port.

How does it compare to existing Gameboy Advance TV solutions?

The GBA HDMI adapter is a game-changer, providing a large jump in quality compared to the Nintendo Gameboy Player or the ultra rare and expensive N64 WideBoy.

The adapter adds almost no input lag (under 1/16 of a frame) and can be considered a near lagless solution. More importantly, it does not suffer from stutter when a game is scrolling vertically or horizontally. This is because the GBA HDMI adapter is frame-locked to the Gameboy Advance and as a result no frames need to be dropped or duplicated as is the case with the Nintendo Gameboy Player. To achieve this at a compliant HDMI output rate, the GBA is overclocked slightly by about 1%. The HDMI output has been validated with an Astro VA-1809A HDMI protocol analyzer to ensure compatibility with a wide range of TVs and monitors.



Installation Guide and other comments

The kit currently only works with the 40 pin GBA. Adapter boards are currently being worked on that will allow it to work with the 32 pin GBA as well as the GBA SP.

40 pin GBA HDMI Adapter Installation Guide

GBA HDMI User Manual

Note to GB Everdrive X7 users: It is advised to not use the GB Everdrive X7 reset to menu button on the Everdrive cartridge. Using that breaks timing between the HDMI board and the GBA due to the way the Everdrive resets the Gameboy.