You could call dispenseWithoutQuestion(someamount) and the device would spit that amount of cash out so it was obviously tremendously pleasing to test.
Of course you don't get to keep the money, but it is yours for a moment, even if just to count it.
And beyond that, you get to see your code operate a physical machine that you can touch.
How many of us get to do that?
Maybe they used $1s or something.
https://shop.dieboldnixdorf.com/atm-demonstration-currency/p...
(We haven't really had "ATM demonstrations" in a long time specifically, but there was a bit of time in the early adoption era to get a fake card into a customer's hand and let them play with a demonstration machine in your lobby or in an office to get to see how convenient it was to get the play money out. See also the tabletop demonstrator Triton built, the ATM Jr - https://triton.com/about-triton/innovative-history/)
These days we have big, full-colour LCD displays, without armouring. In Lincolnshire UK, where I live thieves just pull the whole ATM out of wall with a (stolen) JCB digger and take it away to be cut open at their leisure. That is if they can find one, of course. For both thief and bank customer ATMs are becoming increasingly rare - though not as rare perhaps as brick-and-mortar bank branches.
• The traditional through-the-wall machines that you can access from outside.
• Inside the branch, heavy duty standalone machines that dispense much more cash and more of a variety of bills. These are only accessible when the branch is open, unless you break glass.
Here is a good example, the Marathon GSAR. You can see the radioactive symbol on the dial.
https://www.marathonwatch.com/products/arctic-edition-large-...
[1] https://www.nytimes.com/2005/01/21/obituaries/walter-b-wrist...
Unlike IBM, Omron specializes in ATM hardware, not bank internal systems. That difference in focus could have mattered.
The IBM representative on our team was working behind the through-the-wall ATM, routing some wires when a customer walked up (you could see them via the camera). Being a prankster, he started talking to her in a robotic voice: "Please insert card", "Please choose a transaction", etc. After a few of these he couldn't hold back any further and started laughing. The customer got the joke and started laughing too: "I knew someone was back there!"
Briefly, he was their first (and only) talking ATM.