Stuff that didn’t fit anywhere else:
misc.tex, misc.pdf

luatex2017.tex, luatex2017.pdf

Times tables:
20times.tex, 20times.pdf
30times.tex, 30times.pdf

Conversions: the numbers from 0–255 in Decimal, Hexadecimal, Octal, Binary, followed by the ASCII characters with their decimal and hexadecimal code points (the ‘Basic Latin’ block of Unicode), then the characters that were added to the ASCII set to cater for west European languages and other things (the ‘Latin-1 Supplement’ block of Unicode).
conversions.tex, conversions.pdf