Game Boy TV Tuner (GB/GBC)

The Game Boy TV Tuner was a peripheral for the Game Boy and Game Boy Color. It's made to receive (analog) television signal through air, but you it has many video inputs, so you can also watch cable TV and use the Game Boy as a screen with this add-on.

The Game Boy version (1991)
When Sega released the Game Gear in 1990, they released a peripheral to watch TV in the console. Nintendo developed a peripheral for the Game Boy to compete with Sega. It was released in 1991, initially only receiving NTSC-J signal (in the Japanese version) in both VHF and UHF in the monochrome 4 greyscale tones Game Boy palette. It had composite, SCART and coaxial video inputs to receive analog video signal or to show the Game Boy screen content in a TV or a computer monitor. Because of memory limitations, framerate is somewhat low and equal for all analog TV formats (NTSC, PAL, SECAM).

Game Boy Color (1998)
Shortly after the Game Boy Color was released, Nintendo released an upgraded version of the Game Boy TV Tuner, now with colour support, using a similar method to the Game Boy Color Spongebob video from Pokémon Yellow Arbitrary Code Execution, updating the colour palette almost every frame. Due to this, FPS usually go somewhat lower than in the monochrome Game Boy version. The GBC version of the Game Boy TV Tuner requires more RAM and clock speed, so it's not compatible with the pre-GBC Game Boy models.

Game Boy version

 * 160x120 (4:3) with 4 greyscale colours (with letterbox due to the 10:9 160x144 Game Boy resolution)
 * 160x144 (streched from 4:3 to 10:9) with 4 greyscale colours
 * 160x144 (with pan and scan from 192x144) with 4 greyscale colours

Colour modes

 * 160x200 (4:3) with a dynamic colour palette from a 15-bit colour palette (with letterbox due to the 10:9 160x144 Game Boy resolution)
 * 160x144 (streched from 4:3 to 10:9) with a dynamic colour palette from a 15-bit colour palette
 * 160x144 (with pan and scan from 192x144) with a dynamic colour palette from a 15-bit colour palette

Monochrome modes (same as the Game Boy version)

 * 160x120 (4:3) with 4 greyscale colours (with letterbox due to the 10:9 160x144 Game Boy resolution)
 * 160x144 (streched from 4:3 to 10:9) with 4 greyscale colours
 * 160x144 (with pan and scan from 192x144) with 4 greyscale colours