[pvg]

I liked this piece for the attempt to imagine what using an early personal computer was like and getting it wrong in good and interesting ways - statistically nobody had an Apple I and everything later had BASIC and higher level (i.e. not just monitor) CLIs - that was the big selling point. Later there's a bit about maybe using a decimal FP representation and my first thought was 'no, that's nuts' but your mention of the 800XL sent me to the wikipedia page:

"The first is that all numeric values in [Atari] BASIC are stored in floating-point binary coded decimal (BCD) format"