Funny, just yesterday I listened to a podcast were a small part they were talking about retro-computing. They ware talking about AS400 and that they are still i

Funny, just yesterday I listened to a podcast were a small part they were talking about retro-computing. They ware talking about AS400 and that they are still in use, if you think about Amadeus, one of the worldwide flight-booking systems for example. That some banks in their backend still use AS400 and EBCDIC. The thing why these systems are not being updated is more like: never change a winning team. Because you can spend millions to update those systems just to discover that there is an error in your update. So you spent millions for nothing or even worse. The is not real technical benefit for them to update as long as the systems run.