...which is specifically explained in the article! Did it get something wrong?
The (current?) title of the HN news item is:
The Acorn Archimedes was the first desktop to use the ARM architecture
Which is technically incorrect.
It doesn’t even vaguely match the articles title of:
“Why Wait For Apple? Try Out The Original ARM Desktop Experience Today With A Raspberry Pi”
Thanks for the clarification though, it’s much appreciated! As was the article!