FidoNet was a way to knit thousands of independent bulletin board systems into a single message-passing network without any of them needing a permanent connection to anything. A BBS by itself was an island, reachable only by dialing its specific phone number, but a FidoNet board could exchange electronic mail and shared discussions with every other board in the network. It did this by store-and-forward: instead of staying connected, a board would queue up outgoing messages, then have its software place direct-dial phone calls to other boards to hand off the batch and pick up anything waiting in return, after which the messages would hop board to board until they reached their destination.
The network began in 1984 with Tom Jennings, author of the Fido BBS software. As Randy Bush’s primary account of FidoNet’s history records, Jennings wanted to move messages from his MS-DOS Fido board to a friend’s board, so he wrote an external program that handled mail transfer during a designated hour each night. Others running Fido wanted the same capability, and the network grew to roughly two hundred nodes by early 1985 and into the tens of thousands over the following decade, spreading internationally. Because the boards were run by hobbyists and the long-distance calls came out of their own pockets, the late-night transfer window was a practical necessity, timed to cheap overnight phone rates.
Two services defined FidoNet for its users. Netmail was private, person-to-person electronic mail addressed to a specific user at a specific node. Echomail, developed by Jeff Rush in 1986, was public conferencing: a message posted in an echo, the FidoNet term for a discussion topic, was copied from board to board so that participants across the whole network could read and reply, functioning much like the newsgroups of the era. Echomail turned FidoNet from a mail relay into a sprawling distributed conversation, with hundreds of topical echoes on everything from programming to local-interest chat.
Making this work across so many independently operated boards required agreed-upon rules, which FidoNet codified in its own technical standards. The basic standard, FTS-0001, specified the message format and the original session and transfer protocols that two mailers used to recognize each other and hand off mail, building on Christensen’s XMODEM for the actual file transfer; later standards added more efficient transfer protocols, the echomail format, and the structure of the nodelist. The nodelist was the network’s directory: a weekly-updated file listing every active node, its phone number, and its place in a hierarchy of local, regional, and zone coordinators who collected updates and redistributed them. Addressing evolved alongside it into the familiar zone:net/node.point form.
FidoNet mattered because it gave the dispersed BBS world the connective tissue that a single dial-up board lacked, letting an ordinary hobbyist’s home computer participate in worldwide mail and discussion years before most people had any access to the Internet. It was built and run almost entirely by volunteers, coordinated through its own written policies and standards rather than any company, which made it both remarkably resilient and prone to the governance disputes that come with volunteer hierarchies. As Internet access reached individuals in the mid-1990s, much of FidoNet’s traffic migrated to email and Usenet, but for a decade it had been one of the largest amateur computer networks in the world and a working demonstration that ordinary people could build a global network out of phone calls and shared agreements.