So you don’t think that legacy systems are real? Consider a report from the U.S. Government Accountability Office (GAO-16-696T), published in May 2016. They have a number of examples, of really *old* systems, but one really stand out. The first is “Strategic Automated Command and Control System” at US DoD. It coordinates the operational functions of the United States’ nuclear forces, and is 53 years old. It runs on a IBM Series/1 Computer which has 8″ floppy disk drives. Here’s what a Series/1 system looks like.
On a positive note, these machines are likely not hackable, as they probably aren’t connected to the net. Also to take into consideration, that “modernizing” these systems can be fraught with problems such as poor software design. Then there is also which language? So Cobol is too old at nearly 60 years? What about C, it’s 45? Java, it’s a young 22, but isn’t exactly designed for business transactions like Cobol is. Now, of course the ultimate catch-22 is the hardware-software interdependence. Replacing old hardware means upgrading software… or vice-versa. Maybe easier to just keep the old system, which has 99.999% uptime running?