I’ve finished the pdf of the manual for some of the the Legend RAMcards.
It covers the S’card, 128KDE and 64KC. The card and manual are preProDOS
but does discuss using the card with SOS and the Apple III.
The manual can be downloaded from my site at
http://homepage.mac.com/wayne_stewart
or directly with this link
http://homepage.mac.com/wayne_stewart/.Public/manuals/legend_ramcard.pdf


Wayne