This is great, TFS. Interesting to read period ATM deployment costs (USD$100K) vs. bank branch rollout costs (USD$1M): I see modern parallels to our space (fully automated contactless food preparation and retail). Also interesting to see frank admission of extreme SPOFs: There are over 300 banks in Texas on CIRRUS, but they're all connected to a single node. Interesting how ridiculously inertia driven the whole banking industry is, when you compare modern ATM interfaces to statements like We support withdrawls and balance inquiry from checking, savings and line-of-credit accounts. [...] We're planning to do automatic currency conversion for international transactions. Even on the other side of the world here in China, that basically defines the menu options available today some 40 years later. And the original HQ was Detroit! Oh how the mighty have fallen...

Also amazing: they only targeted 95% uptime (excluding 12 Federal Reserve bank holidays when they were down anyway) and many banks were unable to even reach that level of service! The switch itself was above 98%. This is horrific by today's standards, as was the maximum processing time (45 seconds) and suggested transmission latency allowances (4 seconds). Team size: <1 full time programmer. Code length: 9K lines. TX volume: 50K/month, 4K/day peak.

Further info on TANDEM NONSTOP II hardware which "does not require outages for hardware maintenance" @ https://cs.stanford.edu/people/eroberts/courses/soco/project... ... a few years after this article was written in the subsequent generation TANDEM hardware they added 26MB/sec fiber optic interconnects between the local CPU nodes.

Just a note for anyone else confused by the acronym TFS:

I looked it up on Urban Dictionary and it likely means "Thanks for sharing".

> Even on the other side of the world here in China, that basically defines the menu options available today some 40 years later.

Perhaps this bespeaks a lack of imagination on my part, but I can't imagine many (or really, any) other bank transactions I'd want to conduct while hunching over an ATM rather than in person or online from the comfort of my own home.

The ATMs for my bank in Japan let you do the kind of things online banking allows you to do, like wire transfers, changing your address/phone number, manage loans, make fixed-term deposits. There's a large elderly population which may be more comfortable using an ATM for these features. It's probably safer to use than the average PC too. But it's mostly a holdover from before smartphones and internet banking, where having these features in an ATM was truly useful.

Yeah, my point on inertia was more that you could streamline it greatly by removing all those options to match modern norms.

1. How much cash do you want? 2. $x00 3. Done.

There have been some developments in this direction, but they're the exception rather than the rule.

To a non-American, in Asia, in 2020, particularly if under the age of 30, it is not a strange question to ask "What the hell is a checking account, anyway?"

Ah, right. It's so rare that removal of functionality is seen as a positive that I wasn't thinking in that direction, but yeah, that would be a definite improvement.

I have seen ATMs here in the US that have quick withdrawal options directly on the main menu, but it's usually just one or two preset amounts, and usually from your checking account (since it's still relatively commonplace to have both a savings and a checking account).

Yep. In Hong Kong we have "current accounts" but can still actually order a cheque book - which I did by accident recently and when it arrived want sure what to do with it. Hadn't seen one in years /decades.

Here in Japan you can do bank transfers at ATMs. I'd usually rather do them online but I guess there's a market for it.

> were unable to even reach that level of service

I think ATMs used to be (are?) down in the early hours of the morning every single day.