We’ve come a long way in the last five decades!
This diagram discovered six years ago by @workergnome among his father’s old papers shows ARPAnet as it stood in May 1973
ARPAnet, named after the US Advanced Research Projects Agency (now DARPA), was the precursor to the modern internet
But it is astonishing to think that it began with two computers linked together in California, and within a few years was a network of 42 multi-user computers across the US (including Hawaii, which had a satellite link to California)
Most of those computers were Digital Equipment Corporation’s PDP-series (Programmed Data Processor) minicomputers, though there were also several IBM S/360 and S/370 mainframes and a few others
The IMPs (Interface Message Processors) and TIPs (Terminal Interface Processors) were Honeywell DDP-516 and 316 minicomputers (essentially functioning as what we’d now call routers)