Mention an earlier version of Black Box published by Acornsoft

References:

http://chrisacorns.computinghistory.org.uk/docs/Acorn/Misc/Acornsoft_ProgsforAtom.pdf
https://www.beebgames.com/companies/acornsoft/

I have no idea if that was the first one.

puzzles.but

@@ -1684,7 +1684,9 @@ computer's. So in the above example, you could put the fifth ball at
 \e{any} of the locations marked with an \cw{x}, and you would still
 win.
 
-Black Box was contributed to this collection by James Harvey.
+Acornsoft published versions of Black Box for the Acorn Atom and the
+BBC Microcomputer in the early 1980s.  The puzzle was contributed to
+this collection by James Harvey.
 
 \H{blackbox-controls} \i{Black Box controls}