I can't figure out how to contribute to the wiki, so I am noting here that the manual for RBASIC is available from the Internet Archive in PDF and other formats at https://archive.org/details/RbasicManual (my intent was to add this link to the page http://bitchin100.com/wiki/index.php?title=RBASIC)
The web site for King Computer Services still exists as listed but they are not responsive to emails. Their online ordering page list COBOL products. Happy New Year! rcs
