Airline systems are some of the oldest computing architectures in use.
The Sabre reservation system was created by IBM for American Airlines in the 1950s — when a computer filled an entire building floor and was built out of vacuum tubes — and remains actively used today by multiple airlines. The programming language has been switched several times over the past 60+ years, but essential compatibility remains.
I can't remember where I read this and I can't find a cite right away, but I bet someone can confirm-or-correct me: the 6-letter reservation code for your flight? That used to be an explicit pointer of memory in oldold Sabre.
The Sabre reservation system was created by IBM for American Airlines in the 1950s — when a computer filled an entire building floor and was built out of vacuum tubes — and remains actively used today by multiple airlines. The programming language has been switched several times over the past 60+ years, but essential compatibility remains.