Some people just can't stop tinkering with stuff particularly electrical devices. One group, in particular, decided to play with the FamiCom Mini, Japan's version of the immensely popular NES Classic Edition.
The group in question, known as Kei Studio, was not content merely playing the FamiCom Mini, a miniaturized version of the gaming console popular in Japan in the 80s. They wanted to create an even smaller and more portable version of the console. And thus, the Game Boy version of the FamiCom - the FamiCom Pocket - was born.
The Japanese modders took down a FamiCom Mini and used its parts to create the Game Boy version. They explained the process in details in the video provided. The video was recorded in Japanese but English subtitles were provided.
A boost converter was also used to increase the power to the downscan converter from 5 volts to 12 volts since the monitor required that much. The power came from a mobile battery.
A couple of tiny speakers were attached to the downward converter along with a headphone amplifier to provide steady sounds. It gets a little more complicated after this point so refer to the video for further details.
The original Game Boy came with a gray scale palette which caused problems for players when the light is not enough. The makers of the FamiCom Pocket solved the problem by replacing the old screen with a 3.5-inch LCD display. They then used a downscan converter to convert HDMI signals to composite signals to make tiny monitor compatible.
The only problem with the Game Boy FamiCom, according to Gizmodo, is that it doesn't play actual Game Boy games. That said, fans of the popular handheld console may want to look elsewhere to relive their glory days. But what's great about the re-created FamiCom/Game Boy is that users get to play with NES and FamiCom games in full 8-bit color glory in a portable handheld device.