That's now part of the core documentation: "perlunitut - Perl Unicode Tutorial". The specific section linked is: "I/O flow (the actual 5 minute tutorial)".

I had a very quick scan through the text. Although it looks to be much the same, there may well have been updates (improvements, corrections, etc.) since "perlunitut: Unicode in Perl" was written (16 years ago).

From: "Re^4: UTF-8 and Unicode the hard way":

"(OP here -- sorry, I should have obtained a username before starting this)"

Yes, please do. It'll allow you to edit your posts and us to differentiate you from other AMs.