When was the first Ticket Vending Machine introduced? I don't know - but I did find an
old forum thread started 10 years ago today - on
11th January 2012, with John pointing out that they were still very much "average weather only" machines - which were not usable in very cold weather, very bright weather, or in the rain. Those issues sound familiar ever to this day - and from this morning I can add "in the dark" - it's a good job I knew what the unlit buttons are on the credit card pad do and how they are layed out.
Early
TVMs▸ - such as the London Underground one pictured - were simple one where the put in your money to the machine for the correct price in a line. I can recall them marked 3d and 4d and 6d for central London journeys. By the time the one pictured had been brought into use, inflation had driven the price up to 40p (and there was a 70p machine next to it) but the mechanism was simple - in essence they were queue busters for the ticket office, selling only the most popular journey and leaving more complex sales for the human behind the window.
TVMs still have many characteristics of the queue-busting old days. They still sell much less than a full range of tickets, they still require you to be somewhat knoweldgable about your journey, and they'll still fail to operate properly in the wrong weather of at the wrong time of day. There is a difference in that the safety net of the manned ticket office has largely gone, replaced but not in all aspects by online sales.