Don't fix what isn't broken: https://www.tomshardware.com/desktops/indiana-bakery-still-using-commodore-64s-originally-released-in-1982-as-point-of-sale-terminals

In my professional opinion this is the best malware protected setup I have seen for years.

Indiana bakery still using Commodore 64s originally released in 1982 as cash registers — Hilligoss Bakery in Brownsburg sticks to the BASICs

If it ain't broke...

Tom's Hardware
@masek there was a pool supply store near me that used an Apple II to calculate chemical adjustments based on pool water sample tests until they closed ca. 2020.