Editing Prime Computer (section)

==Electronic messaging==
Electronic messaging was developed on ''relay.prime.com'', which was the hub that relayed global [[email|electronic mail]] for Prime Computer. The software used on this [[computer system]], PDN Mail, developed by Robert Ullmann, was designed to use the encoding header field that was later explained in a [[Request for Comments]].<ref>[https://tools.ietf.org/html/rfc1154 RFC1154]</ref> PDN Mail was also used by [[Microsoft|Microsoft Corporation]] until [[MIME]] was introduced.

Before MIME existed, PDN Mail was able to perform the same functions and was used to send software updates as well as all sorts of attachments between systems. In August 1993, Robert Ullmann, David Robinson and Al Costanzo wrote RFC 1505. This RFC, documented the Encoding Header Field for Internet Messages that PDN mail used and was published by the RFC editor, [[Jon Postel]] that same year.