In this video, I look at an Original Macintosh from 1984. I open the case, I look at the accessories and also the ImageWriter I printer. I look at software including MacWrite, MacPaint and a few games.
I converted a 720p video to 40×40, applied the custom palette and then converted it back to 720p with nearest neighbor resampling. The resulting video retains the 16:9 aspect ratio of the original video.
The original Macintosh computers had a resolution of 512×342 and could display each pixel as either white or black. I converted a 720p video to 512×342 with 1 bit color (b&w). I then added a border to bring the video resolution up to 1280×720 (720p). When viewed at 720p, you should see approximately what it would have looked like on an original Macintosh if the Mac could have played video. Unfortunately compression algorithms used by YouTube can blend the pixels so you may not get the desired effect.