Also for $49, you can get a custom-made HDMI adapter: Play NES in glorious 1080p. The HDMI Adapter is an external RGB to HDMI upscaler designed exclusively for the Analogue Nt.

Retro-Bit's Super RetroTrio Plus can play NES, SNES, and Sega Genesis cartridges and output them at 720p over HDMI, but the upscaling makes 16-bit games look a bit soft.

First, the form factor lets you use any HDMI cable to connect your game system to the upscaler. It adds flexibility by not tying the upconversion to a single cable.

Retro-Bit's Super RetroTrio Plus can play NES, SNES, and Sega Genesis cartridges and output them at 720p over HDMI, but the upscaling makes 16-bit games look a bit soft.