[Jonathan Cauldwell] has come up with just such a tool that lets you do just that, for a variety of 8-bit platforms ... which [Jonathan] explores in a video tutorial series.
UPDATE****: <a href=" Photoshop CC 2017 tutorial showing how create fun, retro, 8-bit, pixel portrait from photos. ➤ Get 15% off BORIS FX OPTICS! - The BEST special effects plug-in for PHOTOS in ...