Free OpenServer appeared in 1996. The cash registers were running on the x86 platform, for sure (68000 was a dead architecture for general purpose computing by then - Apple had been on POWER for several years).
I'm talking more like the late 80s when I was giving my address info to clerks at Rat Shack who were typing it into some kind of green-screen app on what, if memory serves, kinda looked like a Wyse terminal.
Agreed, that would make the conversation quite lively.
Unfortunately, anyone who managed or worked on a curses app that relayed store sales data to a corporate database would need an exceptional memory in their retirement.
https://www.eetimes.com/sco-provides-free-unix-system-licens...