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 wonder if anyone's ever played some Comic Bakery on those C64's at one point or another...