My father worked in a district heating plant. The control PC was 80286 and had uptime over 10 years. Though the plant in theory could be run without it with kno

My father worked in a district heating plant. The control PC was 80286 and had uptime over 10 years. Though the plant in theory could be run without it with knobs and levers. It was replaced by a Pentium with a virtualized MS-DOS due to y2k event, though I am quite sure nothing changed in the underlying MS-DOS program that was more or less time independent.