Hoard-of-bitfonts: bitmap fonts from disused operating systems
I still have my original Interact computer which is not listed. The text on that is 5x5 pixel characters with 1 pixel in between, so 6x6 but the gap is not encoded in the font. Only upper case characters were supported. The font is not in a separate prom, it's in the main 2K eprom along with the tape read/write functions and some very simple keyboard scanning and pixel, box, and text rendering functions. I think a ROM dump exists somewhere online, so with the above description someone should be able to locate the character set easily enough. Probably the worst one you'll ever see.