I don't believe that John has any personal or business web site. As I recall, his Assembler text book has been placed on various web sites (including Marist college, but I don't have a link). His SHARE presentations are available on their web site: https://www.share.org
Last night, I received the following from John's wife: "A John Ehrman website was set up by Len Shustek, who John and I have known since 1967 when Len was a Stanford Graduate Student, assigned to SLAC. Len is the founder and Executive Director of the Computer History Museum." See https://www.forevermissed.com/john-ehrman
