I always wonder how these relics make any money using systems that old. To do business with some of our clients, they audit us for ISO 27001 compliance once per year. Anything out of support would be flagged and we could lose a lot of business.
It's small grocery store chain in the middle of European nowhere, with about hundred of stores run mostly in small villages. Some of those ancient software was made in-house decades ago for internal ordering from wholesaler (also run by the company) to individual shops. Everything in wholesale warehouse runs on the same DOS thing too, with stock inventory, invoice, ordering, ... There's already plan to (finally!!) put it to sleep and replace with something newer and more flexible, but given how low on resources and manpower the company is, it's not going to happen fast.