[Coco] 6309 question

[Torsten Dittel]

I guess this has been discussed a zillion times before, but...

I wonder if this Japanese guy who first published the 6309's hidden
features in English made this completely. What I understand is he only
was remembering something he once read in a Japanese magazine. Has there
ever been a complete translation of that article? Has there ever been
any official document by Hitachi?

Torsten