Review week 31: furnace

The week at the furnace:

• The furnace: Temperature, Pressure, RecipeHash (not 0 = valid melt), Activate ignites, Open opens the mould. Mode is only the display on the device.
• Alloys: mixing ratio plus temperature and pressure window, as defines at the top of the code.
• Control: fuel and exhaust via pumps, two hystereses, the pressure locks the fuel.
• Advanced furnace: SettingInput and SettingOutput in litres per tick, P controller with clamp.
• lr: Contents, Required, Recipe, TotalContents – and never Required on a furnace.

You pass from 60 %.