Even the early electronics where quite différent. I have had to replace the 'logic' that drove the electric motors of a drilling rig built only 35 years ago. About a hundred of buttons and seniors came, as as many wires, 24v or 0v for 1 or 0, in 4 electrical cabinets, each bigger that a fridge. In there, there where hundreds of big old relais, doing all the AND, OR, NOT, boolean operations to combine all those conditions All this for 4 motors. We replaced it by a simple industrial PLC, about the size of à computer, smaller that just the terminals the connect all the inbound and outbound signals. It was fun retro engineering the logical conditions from the relay wiring, then rewriting them
Even the early electronics where quite différent.
I have had to replace the 'logic' that drove the electric motors of a drilling rig built only 35 years ago. About a hundred of buttons and seniors came, as as many wires, 24v or 0v for 1 or 0, in 4 electrical cabinets, each bigger that a fridge. In there, there where hundreds of big old relais, doing all the AND, OR, NOT, boolean operations to combine all those conditions
All this for 4 motors.
We replaced it by a simple industrial PLC, about the size of à computer, smaller that just the terminals the connect all the inbound and outbound signals.
It was fun retro engineering the logical conditions from the relay wiring, then rewriting them