Hi, I'm not prepared to lay out $200 for these Xerox ROMs, but if I do manage to get them, I'll read and share them. I did not know there were 5.0 ROMs for the 820-II, but it appears there were, and they are included.
https://www.ebay.com/itm/184980603844 Mark -- Mark G. Thomas <m...@misty.com>, KC3DRE