Early electronic cash registers
I don't know much about this yet. Electronic cash registers appear to have appeared in the early 70s, but given the prevalence of tube-based and early transistor-based desktop calculators with computer-style flavors in the mid-late 60s, I have the feeling they were around by 1969.
A lot of info on these is scattered around the Vintage Point Of Sale blog.
https://www.youtube.com/watch?v=gR46VzCAZ8I seems to be a good contemporary (70s) piece of footage including NCR registers that, from their bulk, I suspect are self-contained rather than terminals for a backroom server.
I am not sure of the details on the above but I think this DTS machine is from the mid-late 70s, and is a standalone register, not a terminal for a backroom server.
More information on the DTS lineup (though not this model) can be found on the Vintage POS blog.