The full documentation used to be at https://www.icl1900.co.uk/unix4fun/z80pack which sadly has now gone away, so the link in README.md should be updated.
A possible long term solution could be to move the content into github pages (similar to that I have my resume available in a git repository which Github makes available on https://ravn.github.io/cv/). I could give it a go if the original content could be made available, or - plan B - restore from a copy or Internet archive.
The full documentation used to be at https://www.icl1900.co.uk/unix4fun/z80pack which sadly has now gone away, so the link in README.md should be updated.
A possible long term solution could be to move the content into github pages (similar to that I have my resume available in a git repository which Github makes available on https://ravn.github.io/cv/). I could give it a go if the original content could be made available, or - plan B - restore from a copy or Internet archive.