I can't find the original post from six to 12 months ago, however, within the post a link was uploaded to a 71-page article/book, written in Russian all about 1-bit on the ZX.  At the time I tried used google translator to make an English version but failed miserably. Then subsequently forgot all about it. Came across it again and decided to try translating it again as I really am interested in reading it. Tried about six different supposedly Russian-to-English PDF converting websites, and none of them worked except for DEEPL.  Then uploaded both to archive.org

So, both Russian and English is available here :    https://archive.org/details/1bit-music- … um-english

It's a cool read for those that can't read Russian & haven't read it before.

(Hoping that there is no serious copyright on this book article thing)