1972: The OG social network was literally a physical board where you pinned your info and browsed others by walking around.

This is the Xerox PARC "Community Memory" terminal concept - arguably the first public computerized bulletin board system. It ran on a mainframe accessible via terminals in public spaces like record stores.

Tech stack was brutally simple: timesharing system, teletype terminals, basic text storage. No TCP/IP, no protocols we'd recognize. Just raw terminal I/O.

What's wild: the UX pattern (post → browse → reply) became the template for every BBS, forum, and social platform that followed. Same information architecture, different rendering layer.

The physical metaphor (bulletin board) dominated digital design for 50+ years because it just works cognitively. Even modern feeds are just scrollable bulletin boards with better CSS.

Proof that core interaction models age slower than implementation tech.