Block checks

Question,

How do vertical coasters, such as fahrenheit, do block checks?

Well, as far as the computer knowing where the trains are, they use proximity sensors just like any other relatively new ride.

they don't stop the train on the lift to they?

No coaster (except Beast, they messed with the blocking system on that so the second lift is the MCBR. The MCBR shed now is no longer a block, just a trim because of all the excess weight added to the trains over the years, it will not make it to the second lift if stopped fully there) will under normal operating condition. They don't dispatch until they know the train will clear the brakes before the train is at the top of the lift.